Minor fixes

src/Composer/Downloader/GitDownloader.php

@@ -71,10 +71,8 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
             if ($this->gitUtil->fetchRefOrSyncMirror($url, $cachePath, $ref) && is_dir($cachePath)) {
                 $this->cachedPackages[$package->getId()][$ref] = true;
             }
-        } else {
-            if (null === GitUtil::getVersion($this->process)) {
-                throw new \RuntimeException('git was not found in your PATH, skipping source download');
-            }
+        } elseif (null === $gitVersion) {
+            throw new \RuntimeException('git was not found in your PATH, skipping source download');
         }
     }
 

src/Composer/Util/Hg.php

@@ -20,6 +20,8 @@ use Composer\IO\IOInterface;
  */
 class Hg
 {
+    private static $version = false;
+
     /**
      * @var \Composer\IO\IOInterface
      */
@@ -90,7 +92,7 @@ class Hg
     {
         if (false === self::$version) {
             self::$version = null;
-            if (0 === $this->process->execute('hg --version', $output) && preg_match('/version (\d+(?:\.\d+)+)/m', $output, $matches)) {
+            if (0 === $process->execute('hg --version', $output) && preg_match('/version (\d+(?:\.\d+)+)/m', $output, $matches)) {
                 self::$version = $matches[1];
             }
         }