diff --git a/src/SPC/builder/extension/readline.php b/src/SPC/builder/extension/readline.php
index dc4d15f7..939484da 100644
--- a/src/SPC/builder/extension/readline.php
+++ b/src/SPC/builder/extension/readline.php
@@ -27,7 +27,12 @@ class readline extends Extension
 
     public function getUnixConfigureArg(bool $shared = false): string
     {
-        return '--without-libedit --with-readline=' . BUILD_ROOT_PATH;
+        $enable = '--without-libedit --with-readline=' . BUILD_ROOT_PATH;
+        if ($this->builder->getPHPVersionID() < 84000) {
+            // the check uses `char rl_pending_input()` instead of `extern int rl_pending_input`, which makes LTO fail
+            $enable .= ' ac_cv_lib_readline_rl_pending_input=yes';
+        }
+        return $enable;
     }
 
     public function buildUnixShared(): void
diff --git a/src/SPC/builder/linux/LinuxBuilder.php b/src/SPC/builder/linux/LinuxBuilder.php
index da3e12fb..28edeb22 100644
--- a/src/SPC/builder/linux/LinuxBuilder.php
+++ b/src/SPC/builder/linux/LinuxBuilder.php
@@ -104,10 +104,6 @@ class LinuxBuilder extends UnixBuilderBase
             );
         }
 
-        $extra = '';
-        if ($this->getPHPVersionID() < 84000 && $this->getExt('readline') && $this->getLib('libreadline') !== null) {
-            $extra = 'ac_cv_lib_readline_rl_pending_input=yes';
-        }
         shell()->cd(SOURCE_PATH . '/php-src')
             ->exec(
                 $php_configure_env . ' ' .
@@ -122,8 +118,7 @@ class LinuxBuilder extends UnixBuilderBase
                 $json_74 .
                 $zts .
                 $maxExecutionTimers .
-                $this->makeStaticExtensionArgs() . ' ' .
-                $extra
+                $this->makeStaticExtensionArgs() . ' '
             );
 
         $this->emitPatchPoint('before-php-make');
diff --git a/src/SPC/builder/unix/library/librdkafka.php b/src/SPC/builder/unix/library/librdkafka.php
index 3df7a931..e2c3b46e 100644
--- a/src/SPC/builder/unix/library/librdkafka.php
+++ b/src/SPC/builder/unix/library/librdkafka.php
@@ -11,11 +11,7 @@ use SPC\util\executor\UnixAutoconfExecutor;
 
 trait librdkafka
 {
-    /**
-     * @throws FileSystemException
-     * @throws RuntimeException
-     */
-    protected function build(): void
+    public function patchBeforeBuild(): bool
     {
         FileSystem::replaceFileStr(
             $this->source_dir . '/lds-gen.py',
@@ -27,6 +23,15 @@ trait librdkafka
             '#error "IOV_MAX not defined"',
             "#define IOV_MAX 1024\n#define __GNU__"
         );
+        return true;
+    }
+
+    /**
+     * @throws FileSystemException
+     * @throws RuntimeException
+     */
+    protected function build(): void
+    {
         UnixAutoconfExecutor::create($this)
             ->appendEnv(['CFLAGS' => '-Wno-int-conversion -Wno-unused-but-set-variable -Wno-unused-variable'])
             ->optionalLib(
diff --git a/src/SPC/toolchain/ToolchainManager.php b/src/SPC/toolchain/ToolchainManager.php
index ad40b61d..0c92c58a 100644
--- a/src/SPC/toolchain/ToolchainManager.php
+++ b/src/SPC/toolchain/ToolchainManager.php
@@ -5,7 +5,6 @@ declare(strict_types=1);
 namespace SPC\toolchain;
 
 use SPC\builder\linux\SystemUtil;
-use SPC\exception\RuntimeException;
 use SPC\exception\WrongUsageException;
 use SPC\util\GlobalEnvManager;
 use SPC\util\SPCTarget;
@@ -55,10 +54,10 @@ class ToolchainManager
         }
         $musl_wrapper_lib = sprintf('/lib/ld-musl-%s.so.1', php_uname('m'));
         if (SPCTarget::getLibc() === 'musl' && !SPCTarget::isStatic() && !file_exists($musl_wrapper_lib)) {
-            throw new RuntimeException('You are linking against musl libc dynamically, but musl libc is not installed. Please install it with `sudo dnf install musl-libc` or `sudo apt install musl`');
+            throw new WrongUsageException('You are linking against musl libc dynamically, but musl libc is not installed. Please use `bin/spc doctor` to install it.');
         }
         if (SPCTarget::getLibc() === 'glibc' && SystemUtil::isMuslDist()) {
-            throw new RuntimeException('You are linking against glibc dynamically, which is only supported on musl distros.');
+            throw new WrongUsageException('You are linking against glibc dynamically, which is only supported on glibc distros.');
         }
         $toolchain = getenv('SPC_TOOLCHAIN');
         /* @var ToolchainInterface $toolchain */