patman: Update command.Run() to handle failure better

At present tools are not expected to fail. If they do an exception is
raised but there is no detail about what went wrong. This makes it hard
to debug if something does actually go wrong.

Fix this by outputting both stderr and stdout on failure.
Signed-off-by: NSimon Glass <sjg@chromium.org>

tools/patman/tools.py

@@ -205,8 +205,14 @@ def Run(name, *args):
         if tool_search_paths:
             env = dict(os.environ)
             env['PATH'] = ':'.join(tool_search_paths) + ':' + env['PATH']
-        return command.Run(name, *args, capture=True, capture_stderr=True,
-                           env=env)
+        all_args = (name,) + args
+        result = command.RunPipe([all_args], capture=True, capture_stderr=True,
+                                 env=env, raise_on_error=False)
+        if result.return_code:
+            raise Exception("Error %d running '%s': %s" %
+               (result.return_code,' '.join(all_args),
+                result.stderr))
+        return result.stdout
     except:
         if env and not PathHasFile(env['PATH'], name):
             msg = "Please install tool '%s'" % name