More explicit error message

More explicit error message

When running an executable fails, the original error message sent by
the OS is printed, together with a more detailed suggested solution.

BUG=

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=266908

[Ryan Tseng, 2014-04-21 21:50:29]

lgtm + maruel for owners stamp

https://codereview.chromium.org/245133003/diff/1/subprocess2.py
File subprocess2.py (right):

https://codereview.chromium.org/245133003/diff/1/subprocess2.py#newcode251
subprocess2.py:251: raise OSError(('Execution failed with error: %s. '
nit: a \n at the end here would probably be good.
Also the inner parens aren't necessary.
('foo '
 'baz'
 % bar)
will work.

[pgervais, 2014-04-29 17:10:27]

On 2014/04/21 21:50:29, Ryan T. wrote:
> lgtm + maruel for owners stamp
> 
> https://codereview.chromium.org/245133003/diff/1/subprocess2.py
> File subprocess2.py (right):
> 
> https://codereview.chromium.org/245133003/diff/1/subprocess2.py#newcode251
> subprocess2.py:251: raise OSError(('Execution failed with error: %s. '
> nit: a \n at the end here would probably be good.
> Also the inner parens aren't necessary.
> ('foo '
>  'baz'
>  % bar)
> will work.

Marc-Antoine, can I have your lgtm?

[M-A Ruel, 2014-04-29 17:19:22]

sorry, totally missed it, lgtm.

https://codereview.chromium.org/245133003/diff/20001/subprocess2.py
File subprocess2.py (right):

https://codereview.chromium.org/245133003/diff/20001/subprocess2.py#newcode252
subprocess2.py:252: 'Check that %s or %s exist and have execution permission.'
optional: if you want to be more helpful, you could call os.path.isfile() first,
then os.access(, os.X_OK) and change the message accordingly.

[pgervais, 2014-04-29 17:26:58]

Thanks for the review

https://codereview.chromium.org/245133003/diff/20001/subprocess2.py
File subprocess2.py (right):

https://codereview.chromium.org/245133003/diff/20001/subprocess2.py#newcode252
subprocess2.py:252: 'Check that %s or %s exist and have execution permission.'
On 2014/04/29 17:19:23, M-A Ruel wrote:
> optional: if you want to be more helpful, you could call os.path.isfile()
first,
> then os.access(, os.X_OK) and change the message accordingly.

That would indeed be cleaner, but str(e) gives that information already.

[pgervais, 2014-04-29 17:27:03]

The CQ bit was checked by pgervais@chromium.org

[commit-bot: I haz the power, 2014-04-29 17:27:42]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pgervais@chromium.org/245133003/20001

[commit-bot: I haz the power, 2014-04-29 17:29:19]

Change committed as 266908