diff --git a/bin/compile b/bin/compile
index 59e420f3a..1e2e4be1c 100755
--- a/bin/compile
+++ b/bin/compile
@@ -4,16 +4,28 @@
 $cwd = getcwd();
 assert(is_string($cwd));
 chdir(__DIR__.'/../');
-$ts = rtrim(shell_exec('git log -n1 --pretty=%ct HEAD'));
+$ts = rtrim(exec('git log -n1 --pretty=%ct HEAD'));
 if (!is_numeric($ts)) {
     echo 'Could not detect date using "git log -n1 --pretty=%ct HEAD"'.PHP_EOL;
     exit(1);
 }
 // Install with the current version to force it having the right ClassLoader version
 // Install without dev packages to clean up the included classmap from phpunit classes
-shell_exec('php bin/composer config autoloader-suffix ComposerPhar' . $ts);
-shell_exec('php bin/composer install -q --no-dev');
-shell_exec('php bin/composer config autoloader-suffix --unset');
+exec('php bin/composer config autoloader-suffix ComposerPhar' . $ts, $output, $result);
+if (0 !== $result) {
+    echo 'Could not set the autoloader suffix, make sure exec is allowed and php can be found in your PATH';
+    exit(1);
+}
+exec('php bin/composer install -q --no-dev', $output, $result);
+if (0 !== $result) {
+    echo 'Could not remove dev deps, make sure exec is allowed and php can be found in your PATH';
+    exit(1);
+}
+exec('php bin/composer config autoloader-suffix --unset', $output, $result);
+if (0 !== $result) {
+    echo 'Could not remove the autoloader suffix, make sure exec is allowed and php can be found in your PATH';
+    exit(1);
+}
 chdir($cwd);
 
 require __DIR__.'/../src/bootstrap.php';
diff --git a/src/Composer/Command/ConfigCommand.php b/src/Composer/Command/ConfigCommand.php
index b20a4ba81..56ccb5b5e 100644
--- a/src/Composer/Command/ConfigCommand.php
+++ b/src/Composer/Command/ConfigCommand.php
@@ -185,7 +185,7 @@ EOT
 
         $authConfigFile = $input->getOption('global')
             ? ($this->config->get('home') . '/auth.json')
-            : dirname(realpath($configFile)) . '/auth.json';
+            : dirname($configFile) . '/auth.json';
 
         $this->authConfigFile = new JsonFile($authConfigFile, null, $io);
         $this->authConfigSource = new JsonConfigSource($this->authConfigFile, true);
diff --git a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
index 51ac10a8e..5eaa8ee80 100644
--- a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
+++ b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
@@ -1597,7 +1597,10 @@ EOF;
         ));
         $map = $this->generator->buildPackageMap($this->im, $package, array($dep));
         $parsed = $this->generator->parseAutoloads($map, $package);
-        $this->assertSame(array(preg_quote(dirname($this->workingDir)).'/excludedroot($|/)', preg_quote($this->workingDir).'/root/excl($|/)'), $parsed['exclude-from-classmap']);
+        $this->assertSame(array(
+            preg_quote(strtr((string) realpath(dirname($this->workingDir)), '\\', '/')).'/excludedroot($|/)',
+            preg_quote(strtr((string) realpath($this->workingDir), '\\', '/')).'/root/excl($|/)'
+        ), $parsed['exclude-from-classmap']);
     }
 
     public function testEmptyPaths(): void