diff --git a/config/env.ini b/config/env.ini
index 0be1abdfb..f9cde5a08 100644
--- a/config/env.ini
+++ b/config/env.ini
@@ -100,9 +100,10 @@ SPC_TARGET=${GNU_ARCH}-linux-musl
 CC=${SPC_DEFAULT_CC}
 CXX=${SPC_DEFAULT_CXX}
 AR=${SPC_DEFAULT_AR}
+RANLIB=${SPC_DEFAULT_RANLIB}
 LD=${SPC_DEFAULT_LD}
 ; default compiler flags, used in CMake toolchain file, openssl and pkg-config build
-SPC_DEFAULT_CFLAGS="-fPIC -O3 -pipe -fno-plt -fno-semantic-interposition -fstack-clash-protection -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -ffunction-sections -fdata-sections"
+SPC_DEFAULT_CFLAGS="-fPIC -O3 -pipe -fno-plt -fno-semantic-interposition -fstack-clash-protection -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -ffunction-sections -fdata-sections -Wno-unused-command-line-argument"
 SPC_DEFAULT_CXXFLAGS="${SPC_DEFAULT_CFLAGS}"
 SPC_DEFAULT_LDFLAGS="-Wl,-z,relro -Wl,--as-needed -Wl,-z,now -Wl,-z,noexecstack -Wl,--gc-sections"
 ; upx executable path
@@ -125,6 +126,8 @@ SPC_CMD_VAR_PHP_MAKE_EXTRA_CFLAGS="-g -fstack-protector-strong -fno-ident -fPIE
 SPC_CMD_VAR_PHP_MAKE_EXTRA_CXXFLAGS="-g -fstack-protector-strong -fno-ident -fPIE -fvisibility=hidden -fvisibility-inlines-hidden ${SPC_DEFAULT_CXXFLAGS}"
 ; EXTRA_LDFLAGS for `make` php, can use -release to set a soname for libphp.so
 SPC_CMD_VAR_PHP_MAKE_EXTRA_LDFLAGS=""
+; EXTRA_LDFLAGS_PROGRAM for `make` php; appended only to SAPI executable links (cli/fpm/cgi/micro/embed). Used by PGO to inject -fprofile-use= without polluting libphp.{a,so}.
+SPC_CMD_VAR_PHP_MAKE_EXTRA_LDFLAGS_PROGRAM=""
 
 ; optional, path to openssl conf. This affects where openssl will look for the default CA.
 ; default on Debian/Alpine: /etc/ssl, default on RHEL: /etc/pki/tls
@@ -140,6 +143,7 @@ SPC_USE_LLVM=system
 CC=${SPC_DEFAULT_CC}
 CXX=${SPC_DEFAULT_CXX}
 AR=${SPC_DEFAULT_AR}
+RANLIB=${SPC_DEFAULT_RANLIB}
 LD=${SPC_DEFAULT_LD}
 ; default compiler flags, used in CMake toolchain file, openssl and pkg-config build
 SPC_DEFAULT_CFLAGS="--target=${MAC_ARCH}-apple-darwin -O3 -fno-omit-frame-pointer -mno-omit-leaf-frame-pointer -ffunction-sections -fdata-sections"
@@ -163,5 +167,7 @@ SPC_CMD_VAR_PHP_MAKE_EXTRA_CFLAGS="-g -fstack-protector-strong -fpic -fpie -fvis
 SPC_CMD_VAR_PHP_MAKE_EXTRA_CXXFLAGS="-g -fstack-protector-strong -fno-ident -fpie -fvisibility=hidden -fvisibility-inlines-hidden -Werror=unknown-warning-option ${SPC_DEFAULT_CXXFLAGS}"
 ; EXTRA_LDFLAGS for `make` php, can use -release to set a soname for libphp.dylib
 SPC_CMD_VAR_PHP_MAKE_EXTRA_LDFLAGS=""
+; EXTRA_LDFLAGS_PROGRAM for `make` php; appended only to SAPI executable links (cli/fpm/cgi/micro/embed). Used by PGO to inject -fprofile-use= without polluting libphp.{a,dylib}.
+SPC_CMD_VAR_PHP_MAKE_EXTRA_LDFLAGS_PROGRAM=""
 ; minimum compatible macOS version (LLVM vars, availability not guaranteed)
 MACOSX_DEPLOYMENT_TARGET=12.0
diff --git a/config/pkg/ext/ext-brotli.yml b/config/pkg/ext/ext-brotli.yml
index 147ecb636..b87fb9ef3 100644
--- a/config/pkg/ext/ext-brotli.yml
+++ b/config/pkg/ext/ext-brotli.yml
@@ -2,12 +2,13 @@ ext-brotli:
   type: php-extension
   artifact:
     source:
-      type: git
+      type: ghtagtar
+      repo: kjdev/php-ext-brotli
       extract: php-src/ext/brotli
-      rev: master
-      url: 'https://github.com/kjdev/php-ext-brotli'
     metadata:
       license-files: [LICENSE]
       license: MIT
   depends:
     - brotli
+  php-extension:
+    arg-type: '--enable-brotli@shared_suffix@ --with-libbrotli'
diff --git a/config/pkg/ext/ext-zstd.yml b/config/pkg/ext/ext-zstd.yml
index 9b01422be..b07db490c 100644
--- a/config/pkg/ext/ext-zstd.yml
+++ b/config/pkg/ext/ext-zstd.yml
@@ -2,9 +2,8 @@ ext-zstd:
   type: php-extension
   artifact:
     source:
-      type: git
-      url: 'https://github.com/kjdev/php-ext-zstd'
-      rev: master
+      type: ghtar
+      repo: kjdev/php-ext-zstd
       extract: php-src/ext/zstd
     metadata:
       license-files: [LICENSE]
diff --git a/config/pkg/lib/gmssl.yml b/config/pkg/lib/gmssl.yml
index 076234353..ff4250871 100644
--- a/config/pkg/lib/gmssl.yml
+++ b/config/pkg/lib/gmssl.yml
@@ -2,8 +2,9 @@ gmssl:
   type: library
   artifact:
     source:
-      type: ghtar
-      repo: guanzhi/GmSSL
+      type: git
+      url: 'https://github.com/guanzhi/GmSSL.git'
+      rev: master
     metadata:
       license-files: [LICENSE]
       license: Apache-2.0
diff --git a/src/Package/Artifact/gmssl.php b/src/Package/Artifact/gmssl.php
index 4caa4d1e2..833c7b415 100644
--- a/src/Package/Artifact/gmssl.php
+++ b/src/Package/Artifact/gmssl.php
@@ -17,4 +17,11 @@ public function patch(string $target_path): void
         FileSystem::replaceFileStr($target_path . '/src/hex.c', 'unsigned char *OPENSSL_hexstr2buf(const char *str, size_t *len)', 'unsigned char *GMSSL_hexstr2buf(const char *str, size_t *len)');
         FileSystem::replaceFileStr($target_path . '/src/hex.c', 'OPENSSL_hexchar2int', 'GMSSL_hexchar2int');
     }
+
+    #[AfterSourceExtract('ext-gmssl')]
+    #[PatchDescription('Rename pbkdf2_hmac_sm3_genkey() to sm3_pbkdf2() (renamed upstream in GmSSL 3.2+; identical signature)')]
+    public function patchExt(string $target_path): void
+    {
+        FileSystem::replaceFileStr($target_path . '/gmssl.c', 'pbkdf2_hmac_sm3_genkey(', 'sm3_pbkdf2(');
+    }
 }
diff --git a/src/Package/Artifact/go_xcaddy.php b/src/Package/Artifact/go_xcaddy.php
index 51ccfb87b..08bf02d32 100644
--- a/src/Package/Artifact/go_xcaddy.php
+++ b/src/Package/Artifact/go_xcaddy.php
@@ -25,7 +25,6 @@ class go_xcaddy
     ])]
     public function downBinary(ArtifactDownloader $downloader): DownloadResult
     {
-        $pkgroot = PKG_ROOT_PATH;
         $name = SystemTarget::getCurrentPlatformString();
         $arch = match (explode('-', $name)[1]) {
             'x86_64' => 'amd64',
@@ -64,7 +63,7 @@ public function downBinary(ArtifactDownloader $downloader): DownloadResult
         if ($file_hash !== $hash) {
             throw new DownloaderException("Hash mismatch for downloaded go-xcaddy binary. Expected {$hash}, got {$file_hash}");
         }
-        return DownloadResult::archive(basename($path), ['url' => $url, 'version' => $version], extract: "{$pkgroot}/go-xcaddy", verified: true, version: $version);
+        return DownloadResult::archive(basename($path), ['url' => $url, 'version' => $version], extract: '{pkg_root_path}/go-xcaddy', verified: true, version: $version);
     }
 
     #[CustomBinaryCheckUpdate('go-xcaddy', [
@@ -109,7 +108,7 @@ public function afterExtract(string $target_path): void
             'GOROOT' => "{$target_path}",
             'GOBIN' => "{$target_path}/bin",
             'GOPATH' => "{$target_path}/go",
-        ])->exec('CC=cc go install github.com/caddyserver/xcaddy/cmd/xcaddy@latest');
+        ])->exec('CGO_ENABLED=0 go install github.com/caddyserver/xcaddy/cmd/xcaddy@master');
         GlobalEnvManager::addPathIfNotExists("{$target_path}/bin");
     }
 }
diff --git a/src/Package/Extension/event.php b/src/Package/Extension/event.php
index db1192745..2b9515cf7 100644
--- a/src/Package/Extension/event.php
+++ b/src/Package/Extension/event.php
@@ -35,12 +35,37 @@ public function getUnixConfigureArg(PackageInstaller $installer): string
 
     #[BeforeStage('php', [php::class, 'makeForUnix'], 'ext-event')]
     #[PatchDescription('Prevent event extension compile error on macOS')]
+    #[PatchDescription('Patch libevent http_connection.c to use a const peer address')]
     public function patchBeforeMake(PackageInstaller $installer): void
     {
+        $php_src = $installer->getTargetPackage('php')->getSourceDir();
         // Prevent event extension compile error on macOS
         if (SystemTarget::getTargetOS() === 'Darwin') {
-            $php_src = $installer->getTargetPackage('php')->getSourceDir();
             FileSystem::replaceFileRegex("{$php_src}/main/php_config.h", '/^#define HAVE_OPENPTY 1$/m', '');
         }
+        $this->patchLibeventConstPeer("{$php_src}/ext/event");
+    }
+
+    #[BeforeStage('ext-event', [PhpExtensionPackage::class, 'makeForUnix'])]
+    #[PatchDescription('Patch libevent http_connection.c to use a const peer address')]
+    public function patchBeforeSharedMake(PhpExtensionPackage $pkg): void
+    {
+        $this->patchLibeventConstPeer($pkg->getSourceDir());
+    }
+
+    private function patchLibeventConstPeer(string $event_source_dir): bool
+    {
+        $file = "{$event_source_dir}/php8/classes/http_connection.c";
+        if (!is_file($file)) {
+            return false;
+        }
+        // libevent >= 2.2 changed evhttp_connection_get_peer()'s
+        // address arg to `const char **`
+        $header = $this->getBuilder()->getBuildRootPath() . '/include/event2/http.h';
+        $isConst = is_file($header)
+            && preg_match('/evhttp_connection_get_peer\s*\([^;]*\bconst\s+char\s*\*\*\s*address/s', file_get_contents($header)) === 1;
+        return (bool) ($isConst
+            ? FileSystem::replaceFileRegex($file, '/^\tchar \*address;$/m', "\tconst char *address;")
+            : FileSystem::replaceFileRegex($file, '/^\tconst char \*address;$/m', "\tchar *address;"));
     }
 }
diff --git a/src/Package/Extension/rdkafka.php b/src/Package/Extension/rdkafka.php
index 4bb28ee57..2a77ab611 100644
--- a/src/Package/Extension/rdkafka.php
+++ b/src/Package/Extension/rdkafka.php
@@ -49,7 +49,8 @@ public function patchBeforeMake(): bool
     #[CustomPhpConfigureArg('Linux')]
     public function getUnixConfigureArg(bool $shared, PackageBuilder $builder): string
     {
-        $pkgconf_libs = new SPCConfigUtil(['no_php' => true, 'libs_only_deps' => true])->getExtensionConfig($this);
+        $pkgconf_libs = new SPCConfigUtil(['no_php' => true, 'libs_only_deps' => true])
+            ->configForResolvedBuild([$this->getName()], $this->getInstaller());
         return '--with-rdkafka=' . ($shared ? 'shared,' : '') . $builder->getBuildRootPath() . " RDKAFKA_LIBS=\"{$pkgconf_libs['libs']}\"";
     }
 }
diff --git a/src/Package/Extension/swoole.php b/src/Package/Extension/swoole.php
index 10fb19284..70ca033a6 100644
--- a/src/Package/Extension/swoole.php
+++ b/src/Package/Extension/swoole.php
@@ -93,7 +93,8 @@ public function getUnixConfigureArg(bool $shared, PackageBuilder $builder, Packa
         $arg .= $installer->getPhpExtensionPackage('swoole-hook-mysql') ? ' --enable-mysqlnd' : ' --disable-mysqlnd';
         $arg .= $installer->getPhpExtensionPackage('swoole-hook-sqlite') ? ' --enable-swoole-sqlite' : ' --disable-swoole-sqlite';
         if ($installer->getPhpExtensionPackage('swoole-hook-odbc')) {
-            $config = new SPCConfigUtil()->getLibraryConfig($installer->getLibraryPackage('unixodbc'));
+            $config = new SPCConfigUtil(['no_php' => true, 'libs_only_deps' => true])
+                ->configForResolvedBuild(['unixodbc'], $installer);
             $arg .= " --with-swoole-odbc=unixODBC,{$builder->getBuildRootPath()} SWOOLE_ODBC_LIBS=\"{$config['libs']}\"";
         }
 
diff --git a/src/Package/Library/bzip2.php b/src/Package/Library/bzip2.php
index 90fcce7c6..7f99c22b4 100644
--- a/src/Package/Library/bzip2.php
+++ b/src/Package/Library/bzip2.php
@@ -17,7 +17,9 @@ class bzip2
     #[PatchBeforeBuild]
     public function patchBeforeBuild(LibraryPackage $lib): void
     {
-        FileSystem::replaceFileStr($lib->getSourceDir() . '/Makefile', 'CFLAGS=-Wall', 'CFLAGS=-fPIC -Wall');
+        // Makefile pins -O2 -fPIC; inject SPC_DEFAULT_CFLAGS
+        $extra = deduplicate_flags(trim((string) getenv('SPC_DEFAULT_CFLAGS')) . ' -fPIC -Wall');
+        FileSystem::replaceFileStr($lib->getSourceDir() . '/Makefile', 'CFLAGS=-Wall', "CFLAGS={$extra}");
     }
 
     #[BuildFor('Windows')]
diff --git a/src/Package/Library/fastlz.php b/src/Package/Library/fastlz.php
index f9dd010dc..7c3792cd2 100644
--- a/src/Package/Library/fastlz.php
+++ b/src/Package/Library/fastlz.php
@@ -18,9 +18,11 @@ public function build(LibraryPackage $lib): void
     {
         $cc = getenv('CC') ?: 'cc';
         $ar = getenv('AR') ?: 'ar';
+        $extra = trim((string) getenv('SPC_DEFAULT_CFLAGS'));
+        $extra = $extra !== '' ? $extra . ' -fPIC' : '-O3 -fPIC';
 
         shell()->cd($lib->getSourceDir())->initializeEnv($lib)
-            ->exec("{$cc} -c -O3 -fPIC fastlz.c -o fastlz.o")
+            ->exec("{$cc} -c {$extra} fastlz.c -o fastlz.o")
             ->exec("{$ar} rcs libfastlz.a fastlz.o");
 
         // Copy header file
diff --git a/src/Package/Library/icu.php b/src/Package/Library/icu.php
index 7364e94ab..bab245081 100644
--- a/src/Package/Library/icu.php
+++ b/src/Package/Library/icu.php
@@ -24,9 +24,12 @@ public function beforePack(LibraryPackage $lib): void
     #[BuildFor('Linux')]
     public function buildLinux(LibraryPackage $lib, ToolchainInterface $toolchain, PackageBuilder $builder): void
     {
+        // runConfigureICU bakes CXXFLAGS/LDFLAGS, apply user flags too
+        $userCxxFlags = trim((string) getenv('SPC_DEFAULT_CXXFLAGS'));
+        $userLdFlags = trim((string) getenv('SPC_DEFAULT_LDFLAGS'));
         $cppflags = 'CPPFLAGS="-DU_CHARSET_IS_UTF8=1  -DU_USING_ICU_NAMESPACE=1 -DU_STATIC_IMPLEMENTATION=1 -DPIC -fPIC"';
-        $cxxflags = 'CXXFLAGS="-std=c++17 -DPIC -fPIC -fno-ident"';
-        $ldflags = $toolchain->isStatic() ? 'LDFLAGS="-static"' : '';
+        $cxxflags = "CXXFLAGS=\"-std=c++17 -DPIC -fPIC -fno-ident {$userCxxFlags}\"";
+        $ldflags = $toolchain->isStatic() ? "LDFLAGS=\"-static {$userLdFlags}\"" : "LDFLAGS=\"{$userLdFlags}\"";
         shell()->cd($lib->getSourceDir() . '/source')->initializeEnv($lib)
             ->exec(
                 "{$cppflags} {$cxxflags} {$ldflags} " .
diff --git a/src/Package/Library/jbig.php b/src/Package/Library/jbig.php
index 1cfe60b74..94527f457 100644
--- a/src/Package/Library/jbig.php
+++ b/src/Package/Library/jbig.php
@@ -17,7 +17,9 @@ class jbig
     #[PatchBeforeBuild]
     public function patchBeforeBuild(LibraryPackage $lib): void
     {
-        FileSystem::replaceFileStr($lib->getSourceDir() . '/Makefile', 'CFLAGS = -O2 -W -Wno-unused-result', 'CFLAGS = -O2 -W -Wno-unused-result -fPIC');
+        $extra = trim((string) getenv('SPC_DEFAULT_CFLAGS'));
+        $cflags = ($extra !== '' ? $extra : '-O2') . ' -W -Wno-unused-result -fPIC';
+        FileSystem::replaceFileStr($lib->getSourceDir() . '/Makefile', 'CFLAGS = -O2 -W -Wno-unused-result', "CFLAGS = {$cflags}");
     }
 
     #[BuildFor('Darwin')]
diff --git a/src/Package/Library/krb5.php b/src/Package/Library/krb5.php
index 1370afccb..428c6d9b3 100644
--- a/src/Package/Library/krb5.php
+++ b/src/Package/Library/krb5.php
@@ -27,7 +27,7 @@ public function build(LibraryPackage $lib, PackageInstaller $installer, Toolchai
 
         $resolved = array_keys($installer->getResolvedPackages());
         $spc = new SPCConfigUtil(['no_php' => true, 'libs_only_deps' => true]);
-        $config = $spc->getPackageDepsConfig($lib->getName(), $resolved, include_suggests: true);
+        $config = $spc->getPackageDepsConfig($lib->getName(), $resolved);
         $extraEnv = [
             'CFLAGS' => '-fcommon',
             'LIBS' => $config['libs'],
diff --git a/src/Package/Library/libaom.php b/src/Package/Library/libaom.php
index 7e578242b..a896d9b57 100644
--- a/src/Package/Library/libaom.php
+++ b/src/Package/Library/libaom.php
@@ -9,8 +9,10 @@
 use StaticPHP\Package\LibraryPackage;
 use StaticPHP\Runtime\Executor\UnixCMakeExecutor;
 use StaticPHP\Runtime\Executor\WindowsCMakeExecutor;
+use StaticPHP\Runtime\SystemTarget;
 use StaticPHP\Toolchain\Interface\ToolchainInterface;
 use StaticPHP\Toolchain\ZigToolchain;
+use StaticPHP\Util\System\UnixUtil;
 
 #[Library('libaom')]
 class libaom extends LibraryPackage
@@ -39,9 +41,27 @@ public function buildUnix(ToolchainInterface $toolchain): void
             $new = trim($extra . ' -D_GNU_SOURCE');
             f_putenv("SPC_COMPILER_EXTRA={$new}");
         }
+        $targetCpu = SystemTarget::getTargetArch();
+        if (str_starts_with($targetCpu, 'aarch')) {
+            $targetCpu = str_replace('aarch', 'arm', $targetCpu);
+        }
+        if (
+            in_array($targetCpu, ['x86', 'x86_64'], true)
+            && !UnixUtil::findCommand('nasm')
+            && !UnixUtil::findCommand('yasm')
+        ) {
+            $targetCpu = 'generic';
+        }
         UnixCMakeExecutor::create($this)
             ->setBuildDir("{$this->getSourceDir()}/builddir")
-            ->addConfigureArgs('-DAOM_TARGET_CPU=generic')
+            ->addConfigureArgs(
+                "-DAOM_TARGET_CPU={$targetCpu}",
+                '-DCONFIG_RUNTIME_CPU_DETECT=1',
+                '-DENABLE_EXAMPLES=OFF',
+                '-DENABLE_TESTS=OFF',
+                '-DENABLE_TOOLS=OFF',
+                '-DENABLE_DOCS=OFF',
+            )
             ->build();
         f_putenv("SPC_COMPILER_EXTRA={$extra}");
         $this->patchPkgconfPrefix(['aom.pc']);
diff --git a/src/Package/Library/libffi.php b/src/Package/Library/libffi.php
index 351b9076c..e40127fb3 100644
--- a/src/Package/Library/libffi.php
+++ b/src/Package/Library/libffi.php
@@ -8,6 +8,7 @@
 use StaticPHP\Attribute\Package\Library;
 use StaticPHP\Package\LibraryPackage;
 use StaticPHP\Runtime\Executor\UnixAutoconfExecutor;
+use StaticPHP\Runtime\SystemTarget;
 
 #[Library('libffi')]
 class libffi extends LibraryPackage
@@ -28,7 +29,7 @@ public function buildLinux(): void
     #[BuildFor('Darwin')]
     public function buildDarwin(): void
     {
-        $arch = getenv('SPC_ARCH');
+        $arch = SystemTarget::getTargetArch();
         UnixAutoconfExecutor::create($this)
             ->configure(
                 "--host={$arch}-apple-darwin",
diff --git a/src/Package/Library/libheif.php b/src/Package/Library/libheif.php
index 65545f365..19ad4c619 100644
--- a/src/Package/Library/libheif.php
+++ b/src/Package/Library/libheif.php
@@ -24,6 +24,17 @@ public function patchBeforeBuild(LibraryPackage $lib): void
                 'list(APPEND REQUIRES_PRIVATE "libbrotlidec")' . "\n" . '        list(APPEND REQUIRES_PRIVATE "libbrotlienc")'
             );
         }
+        // libheif 1.22+ ships a C-incompatible header: `struct heif_bad_pixel`
+        $heif_properties = $lib->getSourceDir() . '/libheif/api/libheif/heif_properties.h';
+        if (file_exists($heif_properties)
+            && str_contains(file_get_contents($heif_properties), 'struct heif_bad_pixel { uint32_t row; uint32_t column; };')
+        ) {
+            FileSystem::replaceFileStr(
+                $heif_properties,
+                'struct heif_bad_pixel { uint32_t row; uint32_t column; };',
+                'typedef struct heif_bad_pixel { uint32_t row; uint32_t column; } heif_bad_pixel;'
+            );
+        }
     }
 
     #[BuildFor('Darwin')]
diff --git a/src/Package/Library/ncurses.php b/src/Package/Library/ncurses.php
index dd591a6f9..74e3a30f6 100644
--- a/src/Package/Library/ncurses.php
+++ b/src/Package/Library/ncurses.php
@@ -6,6 +6,8 @@
 
 use StaticPHP\Attribute\Package\BuildFor;
 use StaticPHP\Attribute\Package\Library;
+use StaticPHP\Attribute\Package\PatchBeforeBuild;
+use StaticPHP\Attribute\PatchDescription;
 use StaticPHP\Package\LibraryPackage;
 use StaticPHP\Runtime\Executor\UnixAutoconfExecutor;
 use StaticPHP\Toolchain\Interface\ToolchainInterface;
@@ -16,6 +18,24 @@
 #[Library('ncursesw')]
 class ncurses
 {
+    #[PatchBeforeBuild]
+    #[PatchDescription('Filter clang/zig "N warning(s) generated." line out of MKlib_gen.sh preprocessor pipe')]
+    public function patchBeforeBuild(LibraryPackage $lib): void
+    {
+        // MKlib_gen.sh feeds the C preprocessor's stdout through a sed/awk
+        // pipeline into lib_gen.c. zig-cc/clang emits "N warning(s) generated."
+        // on stdout (not stderr), and that line ends up as invalid C in the
+        // generated source. Filter it out of the pipe before sed sees it.
+        $mklibGen = $lib->getSourceDir() . '/ncurses/base/MKlib_gen.sh';
+        if (is_file($mklibGen) && !str_contains((string) file_get_contents($mklibGen), "| grep -v ' generated")) {
+            FileSystem::replaceFileStr(
+                $mklibGen,
+                '$preprocessor $TMP 2>/dev/null \\',
+                "\$preprocessor \$TMP 2>/dev/null \\\n| grep -v ' generated\\.\$' \\",
+            );
+        }
+    }
+
     #[BuildFor('Darwin')]
     #[BuildFor('Linux')]
     public function build(LibraryPackage $package, ToolchainInterface $toolchain): void
@@ -45,6 +65,7 @@ public function build(LibraryPackage $package, ToolchainInterface $toolchain): v
             '--without-tests',
             '--without-dlsym',
             '--without-debug',
+            '--disable-stripping',
             '--enable-symlinks',
             "--with-terminfo-dirs={$terminfo_dirs}",
             "--bindir={$package->getBinDir()}",
diff --git a/src/Package/Library/openssl.php b/src/Package/Library/openssl.php
index f673bb67f..fbde9cf24 100644
--- a/src/Package/Library/openssl.php
+++ b/src/Package/Library/openssl.php
@@ -11,6 +11,7 @@
 use StaticPHP\Package\PackageBuilder;
 use StaticPHP\Package\ToolPackage;
 use StaticPHP\Registry\PackageLoader;
+use StaticPHP\Runtime\SystemTarget;
 use StaticPHP\Util\FileSystem;
 use StaticPHP\Util\System\LinuxUtil;
 
@@ -57,7 +58,11 @@ public function buildWin(LibraryPackage $lib, PackageBuilder $builder): void
     public function buildForDarwin(LibraryPackage $pkg): void
     {
         $zlib_libs = $pkg->getInstaller()->getLibraryPackage('zlib')->getStaticLibFiles();
-        $arch = getenv('SPC_ARCH');
+        $targetArch = SystemTarget::getTargetArch();
+        $arch = match ($targetArch) {
+            'aarch64' => 'arm64',
+            default => $targetArch,
+        };
 
         shell()->cd($pkg->getSourceDir())->initializeEnv($pkg)
             ->exec(
@@ -76,12 +81,7 @@ public function buildForDarwin(LibraryPackage $pkg): void
     #[BuildFor('Linux')]
     public function build(LibraryPackage $lib): void
     {
-        $arch = getenv('SPC_ARCH');
-
-        $env = "CC='" . getenv('CC') . ' -idirafter ' . BUILD_INCLUDE_PATH .
-            ' -idirafter /usr/include/ ' .
-            ' -idirafter /usr/include/' . getenv('SPC_ARCH') . '-linux-gnu/ ' .
-            "' ";
+        $arch = SystemTarget::getTargetArch();
 
         $ex_lib = trim($lib->getInstaller()->getLibraryPackage('zlib')->getStaticLibFiles()) . ' -ldl -pthread';
         $zlib_extra =
@@ -92,9 +92,15 @@ public function build(LibraryPackage $lib): void
         $openssl_dir ??= LinuxUtil::getOSRelease()['dist'] === 'redhat' ? '/etc/pki/tls' : '/etc/ssl';
         $ex_lib = trim($ex_lib);
 
+        // anything we want included (PGO -fprofile-*, LTO, custom hardening)
+        // has to be appended on the command line *after* the target name.
+        $userCFlags = trim((string) getenv('SPC_DEFAULT_CFLAGS'));
+        $userLdFlags = trim((string) getenv('SPC_DEFAULT_LDFLAGS'));
+        $userExtra = trim($userCFlags . ' ' . $userLdFlags);
+
         shell()->cd($lib->getSourceDir())->initializeEnv($lib)
             ->exec(
-                "{$env} ./Configure no-shared zlib " .
+                './Configure no-shared zlib ' .
                 "--prefix={$lib->getBuildRootPath()} " .
                 "--libdir={$lib->getLibDir()} " .
                 "--openssldir={$openssl_dir} " .
@@ -102,7 +108,8 @@ public function build(LibraryPackage $lib): void
                 'enable-pie ' .
                 'no-legacy ' .
                 'no-tests ' .
-                "linux-{$arch}"
+                "linux-{$arch} " .
+                $userExtra
             )
             ->exec('make clean')
             ->exec("make -j{$lib->getBuilder()->concurrency} CNF_EX_LIBS=\"{$ex_lib}\"")
diff --git a/src/Package/Library/postgresql.php b/src/Package/Library/postgresql.php
index 25d600e26..0d8c9ca71 100644
--- a/src/Package/Library/postgresql.php
+++ b/src/Package/Library/postgresql.php
@@ -129,7 +129,7 @@ public function buildWin(LibraryPackage $lib): void
     public function buildUnix(PackageInstaller $installer, PackageBuilder $builder): void
     {
         $spc_config = new SPCConfigUtil(['no_php' => true, 'libs_only_deps' => true]);
-        $config = $spc_config->getPackageDepsConfig('postgresql', array_keys($installer->getResolvedPackages()), include_suggests: $builder->getOption('with-suggests', false));
+        $config = $spc_config->getPackageDepsConfig('postgresql', array_keys($installer->getResolvedPackages()));
 
         $env_vars = [
             'CFLAGS' => $config['cflags'] . ' -std=c17',
diff --git a/src/Package/Target/php/frankenphp.php b/src/Package/Target/php/frankenphp.php
index 854dc8cf8..c2e67c2f8 100644
--- a/src/Package/Target/php/frankenphp.php
+++ b/src/Package/Target/php/frankenphp.php
@@ -122,10 +122,7 @@ public function buildFrankenphpForUnix(TargetPackage $package, PackageInstaller
             $staticFlags = '';
         }
 
-        $resolved = array_keys($installer->getResolvedPackages());
-        // remove self from deps
-        $resolved = array_filter($resolved, fn ($pkg_name) => $pkg_name !== $package->getName());
-        $config = new SPCConfigUtil()->config($resolved);
+        $config = new SPCConfigUtil()->configForResolvedBuild([$package->getName()], $installer);
         $cflags = "{$package->getLibExtraCFlags()} {$config['cflags']} " . getenv('SPC_CMD_VAR_PHP_MAKE_EXTRA_CFLAGS') . " -DFRANKENPHP_VERSION={$frankenphp_version}";
         $libs = $config['libs'];
 
diff --git a/src/Package/Target/php/unix.php b/src/Package/Target/php/unix.php
index 7dcc6d8bb..e306647f5 100644
--- a/src/Package/Target/php/unix.php
+++ b/src/Package/Target/php/unix.php
@@ -590,7 +590,7 @@ public function smokeTestEmbedForUnix(PackageInstaller $installer, ToolchainInte
         copy(ROOT_DIR . '/src/globals/common-tests/embed.c', $sample_file_path . '/embed.c');
         copy(ROOT_DIR . '/src/globals/common-tests/embed.php', $sample_file_path . '/embed.php');
 
-        $config = new SPCConfigUtil()->config($installer->getAvailableResolvedPackageNames());
+        $config = new SPCConfigUtil()->configForResolvedBuild(['php'], $installer);
         $lens = "{$config['cflags']} {$config['ldflags']} {$config['libs']}";
         if ($toolchain->isStatic()) {
             $lens .= ' -static';
@@ -785,7 +785,7 @@ private function processLibphpSoFile(string $libphpSo, PackageInstaller $install
      */
     private function makeVars(PackageInstaller $installer): array
     {
-        $config = new SPCConfigUtil(['libs_only_deps' => true])->config($installer->getAvailableResolvedPackageNames());
+        $config = new SPCConfigUtil(['libs_only_deps' => true])->configForResolvedBuild(['php'], $installer);
         $static = ApplicationContext::get(ToolchainInterface::class)->isStatic() ? '-all-static' : '';
         $pie = SystemTarget::getTargetOS() === 'Linux' ? '-pie' : '';
 
diff --git a/src/Package/Target/php/windows.php b/src/Package/Target/php/windows.php
index 915b1821e..7bfcd53eb 100644
--- a/src/Package/Target/php/windows.php
+++ b/src/Package/Target/php/windows.php
@@ -708,7 +708,7 @@ public function smokeTestEmbedForWindows(PackageInstaller $installer, TargetPack
 
         // Get build configuration using spc-config
         $util = new \StaticPHP\Util\SPCConfigUtil();
-        $config = $util->config(array_map(fn ($x) => $x->getName(), $installer->getResolvedPackages()));
+        $config = $util->configForResolvedBuild(['php'], $installer);
 
         // Build the embed test executable using cl.exe
         // Note: MSVCToolchain already initialized the VC environment, no need for vcvarsall
diff --git a/src/StaticPHP/Artifact/Downloader/Type/GitHubTokenSetupTrait.php b/src/StaticPHP/Artifact/Downloader/Type/GitHubTokenSetupTrait.php
index 412a4c1c3..1850cd5ba 100644
--- a/src/StaticPHP/Artifact/Downloader/Type/GitHubTokenSetupTrait.php
+++ b/src/StaticPHP/Artifact/Downloader/Type/GitHubTokenSetupTrait.php
@@ -14,17 +14,18 @@ public function getGitHubTokenHeaders(): array
     public static function getGitHubTokenHeadersStatic(): array
     {
         // GITHUB_TOKEN support
-        if (($token = getenv('GITHUB_TOKEN')) !== false && ($user = getenv('GITHUB_USER')) !== false) {
+        $token = getenv('GITHUB_TOKEN');
+        if ($token === false || $token === '') {
+            return [];
+        }
+        if (($user = getenv('GITHUB_USER')) !== false && $user !== '') {
             logger()->debug("Using 'GITHUB_TOKEN' with user {$user} for authentication");
             $encoded = base64_encode("{$user}:{$token}");
             spc_add_log_filter([$user, $token, $encoded]);
             return ["Authorization: Basic {$encoded}"];
         }
-        if (($token = getenv('GITHUB_TOKEN')) !== false) {
-            logger()->debug("Using 'GITHUB_TOKEN' for authentication");
-            spc_add_log_filter($token);
-            return ["Authorization: Bearer {$token}"];
-        }
-        return [];
+        logger()->debug("Using 'GITHUB_TOKEN' for authentication");
+        spc_add_log_filter($token);
+        return ["Authorization: Bearer {$token}"];
     }
 }
diff --git a/src/StaticPHP/Doctor/Item/LinuxMuslCheck.php b/src/StaticPHP/Doctor/Item/LinuxMuslCheck.php
index 1fe7ed00d..2d871f0c7 100644
--- a/src/StaticPHP/Doctor/Item/LinuxMuslCheck.php
+++ b/src/StaticPHP/Doctor/Item/LinuxMuslCheck.php
@@ -13,6 +13,7 @@
 use StaticPHP\DI\ApplicationContext;
 use StaticPHP\Doctor\CheckResult;
 use StaticPHP\Runtime\Shell\Shell;
+use StaticPHP\Runtime\SystemTarget;
 use StaticPHP\Toolchain\Interface\ToolchainInterface;
 use StaticPHP\Toolchain\MuslToolchain;
 use StaticPHP\Toolchain\ZigToolchain;
@@ -27,7 +28,14 @@ class LinuxMuslCheck
     public static function optionalCheck(): bool
     {
         $toolchain = ApplicationContext::get(ToolchainInterface::class);
-        return $toolchain instanceof MuslToolchain || $toolchain instanceof ZigToolchain && !LinuxUtil::isMuslDist() && !str_contains(getenv('SPC_TARGET') ?: '', 'gnu');
+        return PHP_OS_FAMILY === 'Linux' && (
+            $toolchain instanceof MuslToolchain || (
+                $toolchain instanceof ZigToolchain
+                && !LinuxUtil::isMuslDist()
+                && SystemTarget::getLibc() === 'musl'
+                && !$toolchain->isStatic()
+            )
+        );
     }
 
     /** @noinspection PhpUnused */
diff --git a/src/StaticPHP/Package/LibraryPackage.php b/src/StaticPHP/Package/LibraryPackage.php
index cd8c626e5..92cd627d7 100644
--- a/src/StaticPHP/Package/LibraryPackage.php
+++ b/src/StaticPHP/Package/LibraryPackage.php
@@ -305,8 +305,8 @@ public function packPrebuilt(): void
      */
     public function getStaticLibFiles(): string
     {
-        $config = new SPCConfigUtil(['libs_only_deps' => true, 'absolute_libs' => true]);
-        $res = $config->config([$this->getName()]);
+        $config = new SPCConfigUtil(['no_php' => true, 'libs_only_deps' => true, 'absolute_libs' => true]);
+        $res = $config->configForResolvedBuild([$this->getName()], $this->getInstaller());
         return $res['libs'];
     }
 
diff --git a/src/StaticPHP/Package/PhpExtensionPackage.php b/src/StaticPHP/Package/PhpExtensionPackage.php
index fef88efd4..68a5b8a33 100644
--- a/src/StaticPHP/Package/PhpExtensionPackage.php
+++ b/src/StaticPHP/Package/PhpExtensionPackage.php
@@ -274,13 +274,13 @@ public function getSharedExtensionEnv(): array
             $compiler_extra = trim($compiler_extra . ' -lcompiler_rt');
             GlobalEnvManager::putenv("SPC_COMPILER_EXTRA={$compiler_extra}");
         }
-        $config = (new SPCConfigUtil())->getExtensionConfig($this);
+        $config = (new SPCConfigUtil())->configForResolvedBuild([$this->getName()], $this->getInstaller());
         [$staticLibs, $sharedLibs] = $this->splitLibsIntoStaticAndShared($config['libs']);
         $preStatic = PHP_OS_FAMILY === 'Darwin' ? '' : '-Wl,--start-group ';
         $postStatic = PHP_OS_FAMILY === 'Darwin' ? '' : ' -Wl,--end-group ';
         return [
             'CFLAGS' => $config['cflags'],
-            'CXXFLAGS' => $config['cflags'],
+            'CXXFLAGS' => $config['cxxflags'],
             'LDFLAGS' => $config['ldflags'],
             'LIBS' => clean_spaces("{$preStatic} {$staticLibs} {$postStatic} {$sharedLibs}"),
             'LD_LIBRARY_PATH' => BUILD_LIB_PATH,
diff --git a/src/StaticPHP/Util/DependencyResolver.php b/src/StaticPHP/Util/DependencyResolver.php
index 129468f92..9833e0672 100644
--- a/src/StaticPHP/Util/DependencyResolver.php
+++ b/src/StaticPHP/Util/DependencyResolver.php
@@ -136,6 +136,52 @@ public static function getSubDependencies(string $package_name, array $resolved_
         return $sorted;
     }
 
+    /**
+     * Get the link closure for one or more roots within an already-resolved package set.
+     *
+     * Both depends and suggests may be traversed, but only packages present in the
+     * resolved set are returned. Dependency overrides add build-specific graph edges,
+     * such as PHP's resolved static extensions and virtual SAPI targets.
+     *
+     * @param  array<Package|string>   $packages
+     * @param  string[]                $resolved_packages
+     * @param  array<string, string[]> $dependency_overrides
+     * @return string[]                Packages in dependency order, including the roots
+     */
+    public static function getResolvedPackageClosure(
+        array $packages,
+        array $resolved_packages,
+        array $dependency_overrides = [],
+        bool $include_suggests = true,
+    ): array {
+        $resolved_set = array_flip($resolved_packages);
+        $dep_map = [];
+        foreach ($resolved_packages as $package) {
+            $dep_map[$package] = [
+                'depends' => array_merge(
+                    PackageConfig::get($package, 'depends', []),
+                    $dependency_overrides[$package] ?? [],
+                ),
+                'suggests' => PackageConfig::get($package, 'suggests', []),
+            ];
+        }
+
+        $visited = [];
+        $sorted = [];
+        foreach ($packages as $package) {
+            $name = is_string($package) ? $package : $package->getName();
+            if (!PackageConfig::isPackageExists($name)) {
+                throw new WrongUsageException("Package '{$name}' does not exist in config, please check your package name !");
+            }
+            if (!isset($resolved_set[$name])) {
+                throw new WrongUsageException("Package '{$name}' is not part of the resolved package set.");
+            }
+            self::visitSubDeps($name, $dep_map, $resolved_set, $include_suggests, $visited, $sorted);
+        }
+
+        return $sorted;
+    }
+
     /**
      * Build a reverse dependency map for the resolved packages.
      * For each package that is depended upon, list which packages depend on it.
diff --git a/src/StaticPHP/Util/SPCConfigUtil.php b/src/StaticPHP/Util/SPCConfigUtil.php
index 63b0e90ef..3c9fa37dd 100644
--- a/src/StaticPHP/Util/SPCConfigUtil.php
+++ b/src/StaticPHP/Util/SPCConfigUtil.php
@@ -7,7 +7,10 @@
 use StaticPHP\Config\PackageConfig;
 use StaticPHP\Exception\WrongUsageException;
 use StaticPHP\Package\LibraryPackage;
+use StaticPHP\Package\Package;
+use StaticPHP\Package\PackageInstaller;
 use StaticPHP\Package\PhpExtensionPackage;
+use StaticPHP\Package\TargetPackage;
 use StaticPHP\Runtime\SystemTarget;
 
 class SPCConfigUtil
@@ -32,95 +35,72 @@ public function __construct(array $options = [])
         $this->absolute_libs = $options['absolute_libs'] ?? false;
     }
 
+    /**
+     * Resolve a standalone package request and generate its configuration.
+     *
+     * This is the entry point for spc-config and callers that do not already have
+     * a PackageInstaller resolution result.
+     *
+     * @param  array<Package|string>                                                  $packages
+     * @return array{cflags: string, cxxflags: string, ldflags: string, libs: string}
+     */
     public function config(array $packages = [], bool $include_suggests = false): array
     {
         // if have php, make php as all extension's dependency
-        if (!$this->no_php) {
-            $dep_override = ['php' => array_filter($packages, fn ($y) => str_starts_with($y, 'ext-'))];
-        } else {
-            $dep_override = [];
-        }
-        $resolved = DependencyResolver::resolve($packages, $dep_override, $include_suggests);
-
-        $ldflags = $this->getLdflagsString();
-        $cflags = $this->getIncludesString($resolved);
-        $libs = $this->getLibsString($resolved, !$this->absolute_libs);
-
-        // additional OS-specific libraries (e.g. macOS -lresolv)
-        // embed
-        if ($extra_libs = SystemTarget::getRuntimeLibs()) {
-            $libs .= " {$extra_libs}";
-        }
+        $package_names = array_map(fn ($package) => is_string($package) ? $package : $package->getName(), $packages);
+        $dep_override = $this->no_php
+            ? []
+            : ['php' => array_values(array_filter($package_names, fn ($name) => str_starts_with($name, 'ext-')))];
 
-        $extra_env = getenv('SPC_EXTRA_LIBS');
-        if (is_string($extra_env) && !empty($extra_env)) {
-            $libs .= " {$extra_env}";
-        }
-        // package frameworks
-        if (SystemTarget::getTargetOS() === 'Darwin') {
-            $libs .= " {$this->getFrameworksString($resolved)}";
-        }
-        // C++
-        if ($this->hasCpp($resolved)) {
-            $target_os = SystemTarget::getTargetOS();
-            if ($target_os === 'Darwin') {
-                $libcpp = '-lc++';
-                $libs = str_replace($libcpp, '', $libs) . " {$libcpp}";
-            } elseif ($target_os !== 'Windows') {
-                // Linux and other Unix-like systems use libstdc++
-                $libcpp = '-lstdc++';
-                $libs = str_replace($libcpp, '', $libs) . " {$libcpp}";
-            }
-            // Windows (MSVC): C++ runtime is linked automatically, no explicit lib needed
-        }
-
-        if ($this->libs_only_deps) {
-            // mimalloc must come first
-            if (in_array('mimalloc', $resolved) && file_exists(BUILD_LIB_PATH . '/libmimalloc.a')) {
-                $libs = BUILD_LIB_PATH . '/libmimalloc.a ' . str_replace([BUILD_LIB_PATH . '/libmimalloc.a', '-lmimalloc'], ['', ''], $libs);
-            }
-            return [
-                'cflags' => clean_spaces(getenv('CFLAGS') . ' ' . $cflags),
-                'ldflags' => clean_spaces(getenv('LDFLAGS') . ' ' . $ldflags),
-                'libs' => clean_spaces(getenv('LIBS') . ' ' . $libs),
-            ];
-        }
+        return $this->configWithResolvedPackages(
+            DependencyResolver::resolve($packages, $dep_override, $include_suggests)
+        );
+    }
 
-        // embed
+    /**
+     * Build configuration for roots within the installer's resolved package graph.
+     *
+     * The installer decides whether suggested packages are enabled. This method always
+     * walks depends and suggests, then filters every edge through that resolved set.
+     *
+     * @param  string[]                                                               $package_names Root package names whose link closure is required
+     * @return array{cflags: string, cxxflags: string, ldflags: string, libs: string}
+     */
+    public function configForResolvedBuild(array $package_names, PackageInstaller $installer): array
+    {
+        $dependency_overrides = [];
         if (!$this->no_php) {
-            if (SystemTarget::getTargetOS() === 'Windows') {
-                // Windows: use php8embed.lib directly (either full path or short name)
-                $major = intdiv(PHP_VERSION_ID, 10000);
-                $php_lib = $this->absolute_libs ? BUILD_LIB_PATH . "\\php{$major}embed.lib" : "php{$major}embed.lib";
-                // Windows system libs required by PHP
-                // Use same system libs as PHP Makefile: LIBS=kernel32.lib ole32.lib user32.lib advapi32.lib shell32.lib ws2_32.lib Dnsapi.lib psapi.lib bcrypt.lib
-                $libs = "{$php_lib} {$libs} kernel32.lib ole32.lib user32.lib advapi32.lib shell32.lib ws2_32.lib dnsapi.lib psapi.lib bcrypt.lib";
-            } else {
-                $libs = "-lphp {$libs} -lc";
+            $php_link_packages = [];
+            foreach ($installer->getResolvedPackages(PhpExtensionPackage::class) as $extension) {
+                if ($extension->isBuildStatic()) {
+                    $php_link_packages[] = $extension->getName();
+                }
             }
+            foreach ($installer->getResolvedPackages(TargetPackage::class) as $target) {
+                if ($target->isVirtualTarget()) {
+                    $php_link_packages[] = $target->getName();
+                }
+            }
+            $dependency_overrides['php'] = $php_link_packages;
         }
 
-        $allLibs = getenv('LIBS') . ' ' . $libs;
-
-        // mimalloc must come first
-        if (in_array('mimalloc', $resolved) && file_exists(BUILD_LIB_PATH . '/libmimalloc.a')) {
-            $allLibs = BUILD_LIB_PATH . '/libmimalloc.a ' . str_replace([BUILD_LIB_PATH . '/libmimalloc.a', '-lmimalloc'], ['', ''], $allLibs);
-        }
-
-        return [
-            'cflags' => clean_spaces(getenv('CFLAGS') . ' ' . $cflags),
-            'ldflags' => clean_spaces(getenv('LDFLAGS') . ' ' . $ldflags),
-            'libs' => clean_spaces($allLibs),
-        ];
+        return $this->configWithResolvedPackages(
+            DependencyResolver::getResolvedPackageClosure(
+                $package_names,
+                array_keys($installer->getResolvedPackages()),
+                $dependency_overrides,
+            )
+        );
     }
 
     /**
      * [Helper function]
      * Get configuration for a specific extension(s) dependencies.
      *
-     * @param array|PhpExtensionPackage $extension_packages Extension instance or list
+     * @param PhpExtensionPackage|PhpExtensionPackage[] $extension_packages Extension instance or list
      * @return array{
      *     cflags: string,
+     *     cxxflags: string,
      *     ldflags: string,
      *     libs: string
      * }
@@ -131,7 +111,7 @@ public function getExtensionConfig(array|PhpExtensionPackage $extension_packages
             $extension_packages = [$extension_packages];
         }
         return $this->config(
-            packages: array_map(fn ($y) => $y->getName(), $extension_packages),
+            packages: array_map(fn ($extension_package) => $extension_package->getName(), $extension_packages),
             include_suggests: $include_suggests,
         );
     }
@@ -140,30 +120,33 @@ public function getExtensionConfig(array|PhpExtensionPackage $extension_packages
      * [Helper function]
      * Get configuration for a specific library(s) dependencies.
      *
-     * @param array|LibraryPackage $lib              Library instance or list
-     * @param bool                 $include_suggests Whether to include suggested libraries
+     * @param LibraryPackage|LibraryPackage[] $library_packages Library instance or list
+     * @param bool                            $include_suggests Whether to include suggested libraries
      * @return array{
      *     cflags: string,
+     *     cxxflags: string,
      *     ldflags: string,
      *     libs: string
      * }
      */
-    public function getLibraryConfig(array|LibraryPackage $lib, bool $include_suggests = false): array
+    public function getLibraryConfig(array|LibraryPackage $library_packages, bool $include_suggests = false): array
     {
-        if (!is_array($lib)) {
-            $lib = [$lib];
+        if (!is_array($library_packages)) {
+            $library_packages = [$library_packages];
         }
         $save_no_php = $this->no_php;
         $this->no_php = true;
         $save_libs_only_deps = $this->libs_only_deps;
         $this->libs_only_deps = true;
-        $ret = $this->config(
-            packages: array_map(fn ($y) => $y->getName(), $lib),
-            include_suggests: $include_suggests,
-        );
-        $this->no_php = $save_no_php;
-        $this->libs_only_deps = $save_libs_only_deps;
-        return $ret;
+        try {
+            return $this->config(
+                packages: array_map(fn ($library_package) => $library_package->getName(), $library_packages),
+                include_suggests: $include_suggests,
+            );
+        } finally {
+            $this->no_php = $save_no_php;
+            $this->libs_only_deps = $save_libs_only_deps;
+        }
     }
 
     /**
@@ -173,23 +156,25 @@ public function getLibraryConfig(array|LibraryPackage $lib, bool $include_sugges
      * library and all its transitive dependencies. It properly handles optional
      * dependencies by only including those that were actually resolved.
      *
-     * @param string   $package_name      The package to get config for
-     * @param string[] $resolved_packages The full resolved package list
-     * @param bool     $include_suggests  Whether to include resolved suggests
+     * @param string   $package_name           The package to get config for
+     * @param string[] $resolved_package_names The full resolved package name list
+     * @param bool     $include_suggests       Whether to include resolved suggests
      * @return array{
      *     cflags: string,
+     *     cxxflags: string,
      *     ldflags: string,
      *     libs: string
      * }
      */
-    public function getPackageDepsConfig(string $package_name, array $resolved_packages, bool $include_suggests = false): array
+    public function getPackageDepsConfig(string $package_name, array $resolved_package_names, bool $include_suggests = true): array
     {
         // Get sub-dependencies within the resolved set
-        $sub_deps = DependencyResolver::getSubDependencies($package_name, $resolved_packages, $include_suggests);
+        $sub_deps = DependencyResolver::getSubDependencies($package_name, $resolved_package_names, $include_suggests);
 
         if (empty($sub_deps)) {
             return [
                 'cflags' => '',
+                'cxxflags' => '',
                 'ldflags' => '',
                 'libs' => '',
             ];
@@ -201,29 +186,36 @@ public function getPackageDepsConfig(string $package_name, array $resolved_packa
         $this->no_php = true;
         $this->libs_only_deps = true;
 
-        $ret = $this->configWithResolvedPackages($sub_deps);
-
-        $this->no_php = $save_no_php;
-        $this->libs_only_deps = $save_libs_only_deps;
-
-        return $ret;
+        try {
+            return $this->configWithResolvedPackages($sub_deps);
+        } finally {
+            $this->no_php = $save_no_php;
+            $this->libs_only_deps = $save_libs_only_deps;
+        }
     }
 
     /**
-     * Get configuration using already-resolved packages (skip dependency resolution).
+     * Generate configuration from an exact, dependency-ordered package list.
+     *
+     * This low-level method does not resolve dependencies or filter packages.
      *
-     * @param string[] $resolved_packages Already resolved package names in build order
+     * @param string[] $resolved_package_names Already resolved package names in build order
      * @return array{
      *     cflags: string,
+     *     cxxflags: string,
      *     ldflags: string,
      *     libs: string
      * }
      */
-    public function configWithResolvedPackages(array $resolved_packages): array
+    public function configWithResolvedPackages(array $resolved_package_names): array
     {
         $ldflags = $this->getLdflagsString();
-        $cflags = $this->getIncludesString($resolved_packages);
-        $libs = $this->getLibsString($resolved_packages, !$this->absolute_libs);
+        $includes = $this->getIncludesString($resolved_package_names);
+        $libs = $this->getLibsString($resolved_package_names, !$this->absolute_libs);
+
+        $cflags = deduplicate_flags(clean_spaces((getenv('SPC_DEFAULT_CFLAGS') ?: '') . ' ' . getenv('CFLAGS') . ' ' . $includes));
+        $cxxflags = deduplicate_flags(clean_spaces((getenv('SPC_DEFAULT_CXXFLAGS') ?: '') . ' ' . getenv('CXXFLAGS') . ' ' . $includes));
+        $ldflags = deduplicate_flags(clean_spaces((getenv('SPC_DEFAULT_LDFLAGS') ?: '') . ' ' . getenv('LDFLAGS') . ' ' . $ldflags));
 
         // additional OS-specific libraries (e.g. macOS -lresolv)
         if ($extra_libs = SystemTarget::getRuntimeLibs()) {
@@ -237,11 +229,11 @@ public function configWithResolvedPackages(array $resolved_packages): array
 
         // package frameworks
         if (SystemTarget::getTargetOS() === 'Darwin') {
-            $libs .= " {$this->getFrameworksString($resolved_packages)}";
+            $libs .= " {$this->getFrameworksString($resolved_package_names)}";
         }
 
         // C++
-        if ($this->hasCpp($resolved_packages)) {
+        if ($this->hasCpp($resolved_package_names)) {
             $target_os = SystemTarget::getTargetOS();
             if ($target_os === 'Darwin') {
                 $libcpp = '-lc++';
@@ -256,40 +248,49 @@ public function configWithResolvedPackages(array $resolved_packages): array
 
         if ($this->libs_only_deps) {
             // mimalloc must come first
-            if (in_array('mimalloc', $resolved_packages) && file_exists(BUILD_LIB_PATH . '/libmimalloc.a')) {
+            if (in_array('mimalloc', $resolved_package_names) && file_exists(BUILD_LIB_PATH . '/libmimalloc.a')) {
                 $libs = BUILD_LIB_PATH . '/libmimalloc.a ' . str_replace([BUILD_LIB_PATH . '/libmimalloc.a', '-lmimalloc'], ['', ''], $libs);
             }
             return [
-                'cflags' => clean_spaces(getenv('CFLAGS') . ' ' . $cflags),
-                'ldflags' => clean_spaces(getenv('LDFLAGS') . ' ' . $ldflags),
+                'cflags' => $cflags,
+                'cxxflags' => $cxxflags,
+                'ldflags' => $ldflags,
                 'libs' => clean_spaces(getenv('LIBS') . ' ' . $libs),
             ];
         }
 
         // embed
         if (!$this->no_php) {
-            $libs = "-lphp {$libs} -lc";
+            if (SystemTarget::getTargetOS() === 'Windows') {
+                $major = intdiv(PHP_VERSION_ID, 10000);
+                $php_lib = $this->absolute_libs ? BUILD_LIB_PATH . "\\php{$major}embed.lib" : "php{$major}embed.lib";
+                $libs = "{$php_lib} {$libs} kernel32.lib ole32.lib user32.lib advapi32.lib shell32.lib ws2_32.lib dnsapi.lib psapi.lib bcrypt.lib";
+            } else {
+                $libs = "-lphp {$libs} -lc";
+            }
         }
 
         $allLibs = getenv('LIBS') . ' ' . $libs;
 
         // mimalloc must come first
-        if (in_array('mimalloc', $resolved_packages) && file_exists(BUILD_LIB_PATH . '/libmimalloc.a')) {
+        if (in_array('mimalloc', $resolved_package_names) && file_exists(BUILD_LIB_PATH . '/libmimalloc.a')) {
             $allLibs = BUILD_LIB_PATH . '/libmimalloc.a ' . str_replace([BUILD_LIB_PATH . '/libmimalloc.a', '-lmimalloc'], ['', ''], $allLibs);
         }
 
         return [
-            'cflags' => clean_spaces(getenv('CFLAGS') . ' ' . $cflags),
-            'ldflags' => clean_spaces(getenv('LDFLAGS') . ' ' . $ldflags),
+            'cflags' => $cflags,
+            'cxxflags' => $cxxflags,
+            'ldflags' => $ldflags,
             'libs' => clean_spaces($allLibs),
         ];
     }
 
-    public function getFrameworksString(array $extensions): string
+    /** @param string[] $package_names */
+    public function getFrameworksString(array $package_names): string
     {
         $list = [];
-        foreach ($extensions as $extension) {
-            foreach (PackageConfig::get($extension, 'frameworks', []) as $fw) {
+        foreach ($package_names as $package_name) {
+            foreach (PackageConfig::get($package_name, 'frameworks', []) as $fw) {
                 $ks = '-framework ' . $fw;
                 if (!in_array($ks, $list)) {
                     $list[] = $ks;
@@ -299,10 +300,11 @@ public function getFrameworksString(array $extensions): string
         return implode(' ', $list);
     }
 
-    private function hasCpp(array $packages): bool
+    /** @param string[] $package_names */
+    private function hasCpp(array $package_names): bool
     {
-        foreach ($packages as $package) {
-            $lang = PackageConfig::get($package, 'lang', 'c');
+        foreach ($package_names as $package_name) {
+            $lang = PackageConfig::get($package_name, 'lang', 'c');
             if ($lang === 'cpp') {
                 return true;
             }
@@ -310,7 +312,8 @@ private function hasCpp(array $packages): bool
         return false;
     }
 
-    private function getIncludesString(array $packages): string
+    /** @param string[] $package_names */
+    private function getIncludesString(array $package_names): string
     {
         $base = BUILD_INCLUDE_PATH;
 
@@ -347,8 +350,8 @@ private function getIncludesString(array $packages): string
 
         // parse pkg-configs (only for Unix)
         if (SystemTarget::isUnix()) {
-            foreach ($packages as $package) {
-                $pc = PackageConfig::get($package, 'pkg-configs', []);
+            foreach ($package_names as $package_name) {
+                $pc = PackageConfig::get($package_name, 'pkg-configs', []);
                 $pkg_config_path = getenv('PKG_CONFIG_PATH') ?: '';
                 $search_paths = array_filter(explode(':', $pkg_config_path));
                 foreach ($pc as $file) {
@@ -360,7 +363,7 @@ private function getIncludesString(array $packages): string
                         }
                     }
                     if (!$found) {
-                        throw new WrongUsageException("pkg-config file '{$file}.pc' for lib [{$package}] does not exist. Please build it first.");
+                        throw new WrongUsageException("pkg-config file '{$file}.pc' for lib [{$package_name}] does not exist. Please build it first.");
                     }
                 }
                 $pc_cflags = implode(' ', $pc);
@@ -386,16 +389,17 @@ private function getLdflagsString(): string
         return '-L' . BUILD_LIB_PATH;
     }
 
-    private function getLibsString(array $packages, bool $use_short_libs = true): string
+    /** @param string[] $package_names */
+    private function getLibsString(array $package_names, bool $use_short_libs = true): string
     {
         $lib_names = [];
         $frameworks = [];
 
-        foreach ($packages as $package) {
+        foreach ($package_names as $package_name) {
             // parse pkg-configs only for unix systems
             if (SystemTarget::isUnix()) {
                 // add pkg-configs libs
-                $pkg_configs = PackageConfig::get($package, 'pkg-configs', []);
+                $pkg_configs = PackageConfig::get($package_name, 'pkg-configs', []);
                 $pkg_config_path = getenv('PKG_CONFIG_PATH') ?: '';
                 $search_paths = array_filter(explode(':', $pkg_config_path));
                 foreach ($pkg_configs as $pkg_config) {
@@ -407,7 +411,7 @@ private function getLibsString(array $packages, bool $use_short_libs = true): st
                         }
                     }
                     if (!$found) {
-                        throw new WrongUsageException("pkg-config file '{$pkg_config}.pc' for lib [{$package}] does not exist. Please build it first.");
+                        throw new WrongUsageException("pkg-config file '{$pkg_config}.pc' for lib [{$package_name}] does not exist. Please build it first.");
                     }
                 }
                 $pkg_configs = implode(' ', $pkg_configs);
@@ -418,12 +422,12 @@ private function getLibsString(array $packages, bool $use_short_libs = true): st
                 }
             }
             // convert all static-libs to short names
-            $libs = array_reverse(PackageConfig::get($package, 'static-libs', []));
+            $libs = array_reverse(PackageConfig::get($package_name, 'static-libs', []));
             foreach ($libs as $lib) {
                 if (FileSystem::isRelativePath($lib)) {
                     // check file existence
                     if (!file_exists(BUILD_LIB_PATH . "/{$lib}")) {
-                        throw new WrongUsageException("Library file '{$lib}' for lib [{$package}] does not exist in '" . BUILD_LIB_PATH . "'. Please build it first.");
+                        throw new WrongUsageException("Library file '{$lib}' for lib [{$package_name}] does not exist in '" . BUILD_LIB_PATH . "'. Please build it first.");
                     }
                     $lib_names[] = $this->getShortLibName($lib);
                 } else {
@@ -432,7 +436,7 @@ private function getLibsString(array $packages, bool $use_short_libs = true): st
             }
             // add frameworks for macOS
             if (SystemTarget::getTargetOS() === 'Darwin') {
-                $frameworks = array_merge($frameworks, PackageConfig::get($package, 'frameworks', []));
+                $frameworks = array_merge($frameworks, PackageConfig::get($package_name, 'frameworks', []));
             }
         }
 
@@ -451,7 +455,7 @@ private function getLibsString(array $packages, bool $use_short_libs = true): st
             }
         }
 
-        if (in_array('imap', $packages) && SystemTarget::getTargetOS() === 'Linux' && SystemTarget::getLibc() === 'glibc') {
+        if (in_array('imap', $package_names) && SystemTarget::getTargetOS() === 'Linux' && SystemTarget::getLibc() === 'glibc') {
             if (file_exists(BUILD_LIB_PATH . '/libcrypt.a')) {
                 $lib_names[] = '-lcrypt';
             }
diff --git a/src/StaticPHP/Util/SourcePatcher.php b/src/StaticPHP/Util/SourcePatcher.php
index 98fee7ec2..430a44edc 100644
--- a/src/StaticPHP/Util/SourcePatcher.php
+++ b/src/StaticPHP/Util/SourcePatcher.php
@@ -173,6 +173,9 @@ public static function unpatchHardcodedINI(string $php_source_dir): bool
      */
     public static function patchMicroPhar(int $version_id): void
     {
+        if (file_exists(SOURCE_PATH . '/php-src/ext/phar/phar.c.bak')) {
+            return;
+        }
         FileSystem::backupFile(SOURCE_PATH . '/php-src/ext/phar/phar.c');
         FileSystem::replaceFileStr(
             SOURCE_PATH . '/php-src/ext/phar/phar.c',
@@ -198,6 +201,12 @@ public static function patchMicroPhar(int $version_id): void
 
     public static function unpatchMicroPhar(): void
     {
+        // Tolerate a missing .bak: both drivers call this, and the first restore
+        // consumes the backup. Without this guard the second call throws
+        // "Cannot find bak file". No .bak means the source is already pristine.
+        if (!file_exists(SOURCE_PATH . '/php-src/ext/phar/phar.c.bak')) {
+            return;
+        }
         FileSystem::restoreBackupFile(SOURCE_PATH . '/php-src/ext/phar/phar.c');
     }
 
diff --git a/tests/StaticPHP/Command/SPCConfigCommandTest.php b/tests/StaticPHP/Command/SPCConfigCommandTest.php
new file mode 100644
index 000000000..3c0d9b859
--- /dev/null
+++ b/tests/StaticPHP/Command/SPCConfigCommandTest.php
@@ -0,0 +1,79 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\StaticPHP\Command;
+
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LogLevel;
+use StaticPHP\Command\SPCConfigCommand;
+use StaticPHP\Config\PackageConfig;
+use StaticPHP\DI\ApplicationContext;
+use Symfony\Component\Console\Application;
+use Symfony\Component\Console\Tester\CommandTester;
+
+/**
+ * @internal
+ */
+class SPCConfigCommandTest extends TestCase
+{
+    protected function setUp(): void
+    {
+        parent::setUp();
+        ApplicationContext::reset();
+        $this->setPackageConfig([
+            'root' => [
+                'type' => 'library',
+                'suggests' => ['optional'],
+                'static-libs' => ['/fixtures/libroot.a'],
+            ],
+            'optional' => [
+                'type' => 'library',
+                'static-libs' => ['/fixtures/liboptional.a'],
+            ],
+        ]);
+    }
+
+    protected function tearDown(): void
+    {
+        $this->setPackageConfig([]);
+        ApplicationContext::reset();
+        logger()->setLevel(LogLevel::ERROR);
+        parent::tearDown();
+    }
+
+    public function testWithSuggestsOptionStillAffectsStandaloneCommand(): void
+    {
+        $withoutSuggests = $this->runCommand(false);
+        $withSuggests = $this->runCommand(true);
+
+        $this->assertStringNotContainsString('/fixtures/liboptional.a', $withoutSuggests);
+        $this->assertStringContainsString('/fixtures/liboptional.a', $withSuggests);
+    }
+
+    private function runCommand(bool $withSuggests): string
+    {
+        $application = new Application();
+        $application->setAutoExit(false);
+        $application->add(new SPCConfigCommand());
+        $tester = new CommandTester($application->find('spc-config'));
+        $input = [
+            '--with-libs' => 'root',
+            '--libs-only-deps' => true,
+            '--no-php' => true,
+            '--no-ansi' => true,
+        ];
+        if ($withSuggests) {
+            $input['--with-suggests'] = true;
+        }
+        $tester->execute($input);
+
+        return $tester->getDisplay();
+    }
+
+    private function setPackageConfig(array $config): void
+    {
+        $reflection = new \ReflectionClass(PackageConfig::class);
+        $reflection->getProperty('package_configs')->setValue(null, $config);
+    }
+}
diff --git a/tests/StaticPHP/Util/DependencyResolverTest.php b/tests/StaticPHP/Util/DependencyResolverTest.php
index b9098c668..ce137de71 100644
--- a/tests/StaticPHP/Util/DependencyResolverTest.php
+++ b/tests/StaticPHP/Util/DependencyResolverTest.php
@@ -412,6 +412,39 @@ public function testGetSubDependenciesOnlyIncludesResolvedDeps(): void
         $this->assertNotContains('c', $subDeps, 'c is not in the resolved set, should be excluded');
     }
 
+    public function testGetResolvedPackageClosureFiltersSuggestsThroughResolvedSet(): void
+    {
+        $this->loadConfig([
+            'a' => ['type' => 'target', 'depends' => ['b'], 'suggests' => ['c']],
+            'b' => ['type' => 'library'],
+            'c' => ['type' => 'library'],
+        ]);
+
+        $withoutSuggested = DependencyResolver::getResolvedPackageClosure(['a'], ['b', 'a']);
+        $withSuggested = DependencyResolver::getResolvedPackageClosure(['a'], ['b', 'c', 'a']);
+
+        $this->assertSame(['b', 'a'], $withoutSuggested);
+        $this->assertSame(['b', 'c', 'a'], $withSuggested);
+    }
+
+    public function testGetResolvedPackageClosureAppliesDependencyOverrides(): void
+    {
+        $this->loadConfig([
+            'php' => ['type' => 'target', 'depends' => ['libxml2']],
+            'libxml2' => ['type' => 'library'],
+            'ext-demo' => ['type' => 'php-extension', 'depends' => ['demo-lib']],
+            'demo-lib' => ['type' => 'library'],
+        ]);
+
+        $closure = DependencyResolver::getResolvedPackageClosure(
+            ['php'],
+            ['libxml2', 'demo-lib', 'ext-demo', 'php'],
+            ['php' => ['ext-demo']],
+        );
+
+        $this->assertSame(['libxml2', 'demo-lib', 'ext-demo', 'php'], $closure);
+    }
+
     // ──────────────────────────────────────────────
     //  Edge cases & defensive
     // ──────────────────────────────────────────────
diff --git a/tests/StaticPHP/Util/SPCConfigUtilTest.php b/tests/StaticPHP/Util/SPCConfigUtilTest.php
new file mode 100644
index 000000000..987104991
--- /dev/null
+++ b/tests/StaticPHP/Util/SPCConfigUtilTest.php
@@ -0,0 +1,207 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\StaticPHP\Util;
+
+use PHPUnit\Framework\TestCase;
+use StaticPHP\Config\PackageConfig;
+use StaticPHP\DI\ApplicationContext;
+use StaticPHP\Exception\WrongUsageException;
+use StaticPHP\Package\LibraryPackage;
+use StaticPHP\Package\Package;
+use StaticPHP\Package\PackageInstaller;
+use StaticPHP\Package\PhpExtensionPackage;
+use StaticPHP\Package\TargetPackage;
+use StaticPHP\Util\SPCConfigUtil;
+
+/**
+ * @internal
+ */
+class SPCConfigUtilTest extends TestCase
+{
+    /** @var array<string, false|string> */
+    private array $savedEnv = [];
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        ApplicationContext::reset();
+        $this->resetPackageConfig();
+        foreach (['CFLAGS', 'CXXFLAGS', 'LDFLAGS', 'LIBS', 'SPC_DEFAULT_CFLAGS', 'SPC_DEFAULT_CXXFLAGS', 'SPC_DEFAULT_LDFLAGS', 'SPC_EXTRA_LIBS'] as $name) {
+            $this->savedEnv[$name] = getenv($name);
+        }
+    }
+
+    protected function tearDown(): void
+    {
+        foreach ($this->savedEnv as $name => $value) {
+            $value === false ? putenv($name) : putenv("{$name}={$value}");
+        }
+        $this->resetPackageConfig();
+        ApplicationContext::reset();
+        parent::tearDown();
+    }
+
+    public function testStandaloneConfigStillControlsSuggestsDuringResolution(): void
+    {
+        $this->loadLinkFixture();
+        $util = new SPCConfigUtil(['no_php' => true, 'libs_only_deps' => true]);
+
+        $withoutSuggests = $util->config(['root']);
+        $withSuggests = $util->config(['root'], include_suggests: true);
+
+        $this->assertStringContainsString('/fixtures/librequired.a', $withoutSuggests['libs']);
+        $this->assertStringNotContainsString('/fixtures/liboptional.a', $withoutSuggests['libs']);
+        $this->assertStringContainsString('/fixtures/liboptional.a', $withSuggests['libs']);
+    }
+
+    public function testResolvedConfigIncludesOnlySuggestedPackagesThatWereResolved(): void
+    {
+        $this->loadLinkFixture();
+        $util = new SPCConfigUtil(['no_php' => true, 'libs_only_deps' => true]);
+
+        $withoutOptional = $util->configForResolvedBuild(['root'], $this->createInstaller([
+            'required' => 'library',
+            'root' => 'library',
+        ]));
+        $withOptional = $util->configForResolvedBuild(['root'], $this->createInstaller([
+            'required' => 'library',
+            'optional' => 'library',
+            'root' => 'library',
+        ]));
+
+        $this->assertStringNotContainsString('/fixtures/liboptional.a', $withoutOptional['libs']);
+        $this->assertStringContainsString('/fixtures/liboptional.a', $withOptional['libs']);
+    }
+
+    public function testResolvedConfigSupportsExplicitPhpLinkClosureOverrides(): void
+    {
+        $this->loadConfig([
+            'php' => ['type' => 'target', 'depends' => ['core']],
+            'core' => ['type' => 'library', 'static-libs' => ['/fixtures/libcore.a']],
+            'ext-demo' => ['type' => 'php-extension', 'depends' => ['ext-lib']],
+            'ext-lib' => ['type' => 'library', 'static-libs' => ['/fixtures/libext.a']],
+            'php-fpm' => ['type' => 'virtual-target', 'depends' => ['php'], 'suggests' => ['fpm-lib']],
+            'fpm-lib' => ['type' => 'library', 'static-libs' => ['/fixtures/libfpm.a']],
+        ]);
+        $util = new SPCConfigUtil(['libs_only_deps' => true]);
+
+        $config = $util->configForResolvedBuild(['php'], $this->createInstaller([
+            'core' => 'library',
+            'ext-lib' => 'library',
+            'ext-demo' => 'static-extension',
+            'fpm-lib' => 'library',
+            'php-fpm' => 'virtual-target',
+            'php' => 'target',
+        ]));
+
+        $this->assertStringContainsString('/fixtures/libcore.a', $config['libs']);
+        $this->assertStringContainsString('/fixtures/libext.a', $config['libs']);
+        $this->assertStringContainsString('/fixtures/libfpm.a', $config['libs']);
+    }
+
+    public function testResolvedConfigRejectsRootOutsideResolvedSet(): void
+    {
+        $this->loadLinkFixture();
+
+        $this->expectException(WrongUsageException::class);
+        $this->expectExceptionMessage("Package 'root' is not part of the resolved package set");
+
+        new SPCConfigUtil(['no_php' => true])->configForResolvedBuild(['root'], $this->createInstaller([
+            'required' => 'library',
+        ]));
+    }
+
+    public function testCAndCxxFlagsRemainIndependent(): void
+    {
+        putenv('SPC_DEFAULT_CFLAGS=-DDEFAULT_C');
+        putenv('SPC_DEFAULT_CXXFLAGS=-DDEFAULT_CXX');
+        putenv('SPC_DEFAULT_LDFLAGS=-Wl,default');
+        putenv('CFLAGS=-DUSER_C');
+        putenv('CXXFLAGS=-DUSER_CXX');
+        putenv('LDFLAGS=-Wl,user');
+
+        $config = new SPCConfigUtil(['no_php' => true, 'libs_only_deps' => true])->configWithResolvedPackages([]);
+
+        $this->assertStringContainsString('-DDEFAULT_C', $config['cflags']);
+        $this->assertStringContainsString('-DUSER_C', $config['cflags']);
+        $this->assertStringNotContainsString('-DDEFAULT_CXX', $config['cflags']);
+        $this->assertStringContainsString('-DDEFAULT_CXX', $config['cxxflags']);
+        $this->assertStringContainsString('-DUSER_CXX', $config['cxxflags']);
+        $this->assertStringContainsString('-Wl,default', $config['ldflags']);
+        $this->assertStringContainsString('-Wl,user', $config['ldflags']);
+    }
+
+    private function loadLinkFixture(): void
+    {
+        $this->loadConfig([
+            'root' => [
+                'type' => 'library',
+                'depends' => ['required'],
+                'suggests' => ['optional'],
+                'static-libs' => ['/fixtures/libroot.a'],
+            ],
+            'required' => ['type' => 'library', 'static-libs' => ['/fixtures/librequired.a']],
+            'optional' => ['type' => 'library', 'static-libs' => ['/fixtures/liboptional.a']],
+        ]);
+    }
+
+    private function loadConfig(array $configs): void
+    {
+        $reflection = new \ReflectionClass(PackageConfig::class);
+        $property = $reflection->getProperty('package_configs');
+        $property->setValue(null, $configs);
+    }
+
+    private function resetPackageConfig(): void
+    {
+        $this->loadConfig([]);
+    }
+
+    /**
+     * @param array<string, 'library'|'static-extension'|'target'|'virtual-target'> $packages
+     */
+    private function createInstaller(array $packages): PackageInstaller
+    {
+        $installer = new PackageInstaller(['no-tracker' => true], false);
+        $resolved = [];
+        foreach ($packages as $name => $type) {
+            $package = match ($type) {
+                'static-extension' => $this->createStaticExtension($name),
+                'target' => $this->createTarget($name, false),
+                'virtual-target' => $this->createTarget($name, true),
+                default => $this->createNamedPackage(LibraryPackage::class, $name),
+            };
+            $resolved[$name] = $package;
+        }
+
+        $reflection = new \ReflectionClass(PackageInstaller::class);
+        $reflection->getProperty('packages')->setValue($installer, $resolved);
+        return $installer;
+    }
+
+    private function createStaticExtension(string $name): PhpExtensionPackage
+    {
+        $extension = $this->createMock(PhpExtensionPackage::class);
+        $extension->method('getName')->willReturn($name);
+        $extension->method('isBuildStatic')->willReturn(true);
+        return $extension;
+    }
+
+    private function createTarget(string $name, bool $virtual): TargetPackage
+    {
+        $target = $this->createMock(TargetPackage::class);
+        $target->method('getName')->willReturn($name);
+        $target->method('isVirtualTarget')->willReturn($virtual);
+        return $target;
+    }
+
+    /** @param class-string<Package> $class */
+    private function createNamedPackage(string $class, string $name): Package
+    {
+        $package = $this->createMock($class);
+        $package->method('getName')->willReturn($name);
+        return $package;
+    }
+}