Re: [RFC PATCH v4 2/3] Show the call history when an alias is looping
- Date: Sat, 8 Sep 2018 12:29:09 -0400
- From: Jeff King <peff@xxxxxxxx>
- Subject: Re: [RFC PATCH v4 2/3] Show the call history when an alias is looping
On Sat, Sep 08, 2018 at 03:34:34PM +0200, Duy Nguyen wrote:
> On Sat, Sep 8, 2018 at 12:44 AM Tim Schumacher <timschumi@xxxxxx> wrote:
> > Just printing the command that the user entered is not particularly
> > helpful when trying to find the alias that causes the loop.
> > Print the history of substituted commands to help the user find the
> > offending alias. Mark the entrypoint of the loop with "<==" and the
> > last command (which looped back to the entrypoint) with "==>".
> An even simpler way to give this information is simply suggest the
> user tries again with GIT_TRACE=1. All alias expansion is shown there
> and we teach the user about GIT_TRACE. But your approach is probably
> more user friendly.
Good point. I'm OK with the amount of code here for the nicer message
(but would be happy either way).
If we were going to track cross-process loops like Ævar suggested, I
think I'd rather go with a simple counter and just ask the user to run
with GIT_TRACE when it exceeds some maximum sanity value. For two
1. Passing a counter through the environment is way simpler than
an arbitrarily-sized list.
2. When you get into multiple processes, there's potentially more
going on than just Git commands. You might have a git command which
runs a hook which runs a third party script which runs a git
command, which runs a hook, and so on. That full dump is going to
be more useful.