diff --git a/src/Composer/Compiler.php b/src/Composer/Compiler.php
index e80a63d78..86c6ffb44 100644
--- a/src/Composer/Compiler.php
+++ b/src/Composer/Compiler.php
@@ -35,9 +35,9 @@ class Compiler
             unlink($pharFile);
         }
 
-        $process = new Process('git log --pretty="%h" -n1 HEAD');
+        $process = new Process('git log --pretty="%h" -n1 HEAD', __DIR__);
         if ($process->run() != 0) {
-            throw new \RuntimeException('The git binary cannot be found or compile was run not inside git repository folder.');
+            throw new \RuntimeException('Can\'t run git log. You must ensure to run compile from composer git repository clone and that git binary is available.');
         }
         $this->version = trim($process->getOutput());
 
diff --git a/src/Composer/Downloader/HgDownloader.php b/src/Composer/Downloader/HgDownloader.php
index 768280845..629883dc8 100644
--- a/src/Composer/Downloader/HgDownloader.php
+++ b/src/Composer/Downloader/HgDownloader.php
@@ -50,7 +50,7 @@ class HgDownloader extends VcsDownloader
     {
         $this->process->execute(sprintf('cd %s && hg st', escapeshellarg($path)), $output);
         if (trim($output)) {
-            throw new \RuntimeException('Source directory has uncommitted changes');
+            throw new \RuntimeException('Source directory ' . $path . ' has uncommitted changes');
         }
     }
 }
diff --git a/src/Composer/Downloader/SvnDownloader.php b/src/Composer/Downloader/SvnDownloader.php
index e0bb915f6..28d3e2101 100644
--- a/src/Composer/Downloader/SvnDownloader.php
+++ b/src/Composer/Downloader/SvnDownloader.php
@@ -51,7 +51,7 @@ class SvnDownloader extends VcsDownloader
     {
         $this->process->execute(sprintf('cd %s && svn status', escapeshellarg($path)), $output);
         if (trim($output)) {
-            throw new \RuntimeException('Source directory has uncommitted changes');
+            throw new \RuntimeException('Source directory ' . $path . ' has uncommitted changes');
         }
     }
 }
\ No newline at end of file