Re: [PATCH 3/5] run-command: Elaborate execvp error checking

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Jan 25, 2012, 19:22 UTC
Message-ID: <20120125192222.GH1824@burratino>
In-Reply-To: <op.v8motzak0aolir@keputer>

Frans Klaver wrote:

> Jonathan Nieder wrote:

Show 7 quoted lines

>> Could you give an example?
>
> The case that triggered me to work on this. I had an incorrect entry
> in my PATH and some aliasing tests failed. The generated command
> output was something like
>
> fatal: script: Access Denied

Sorry for the lack of clarity. I meant that a (precise) "before and after" example could make the commit message a lot easier to understand.

[...]

>> What happens on Windows?
>
> I haven't changed anything on the windows side, so that probably
> sticks to the old behavior.

This was mostly a comment on the change description --- unless I look at the patch, if I try this out on Windows after reading the changelog I would end up utterly confused. For patch 5/5, it also brings up worries about consistency --- if systems are going to be relying on a missing #! interpreter being treated differently from a missing script for the sake of silent_exec_failure, do the same considerations apply on Windows, too?

Perhaps it's more along the lines of "this is not supposed to happen in practice, and when it does, humans will find it easier to debug if we error out hard instead of falling back to the 'if the command does not exist' behavior (e.g., by trying an alias next)". In other words, maybe this is intended as an optional nicety rather than something scripts would ever rely on.

Jonathan