Check compiler exit status.

Author: cyberdelia

pipeline/compilers/__init__.py

@@ -104,4 +104,6 @@ def execute_command(self, command, content=None, cwd=None):
             raise CompilerError(stderr)
         if self.verbose:
             print(stderr)
+        if pipe.returncode != 0:
+            raise CompilerError("Command '%s' returned non-zero exit status %d".format(command, pipe.returncode))
         return stdout