Re: git does not wait on hook exes (^C)

["brian m. carlson" <sandals@crustytoothpaste.net>]

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On 2020-02-21 at 00:12:18, Anthony Sottile wrote:
> On Thu, Feb 20, 2020 at 4:01 PM brian m. carlson
> <sandals@crustytoothpaste.net> wrote:
> > I believe the way that SIGINT works on a terminal is that it sends the
> > signal to all processes in the foreground process group.  So my guess of
> > what's happening here is that Git and your script both get SIGINT, Git
> > cleans up and exits quickly, leaving your script running.
> >
> > If so, I'm not sure that Git can do much here.  If Git waited for the
> > hook to exit, then a broken or hung hook would cause Git to hang
> > indefinitely, which is not what the user intended when they pressed
> > Ctrl-C.  Usually what the user wants is an immediate return to the
> > terminal in such a case, and I think most users would consider it a bug
> > if Git were to wait for its children.
> 
> Taking git out of the situation:
> 
> Create a shell script:
> 
> ```bash
> #!/usr/bin/env bash
> .git/hooks/pre-commit
> ```
> 
> ```console
> $ ./t.sh
> zzz part 1
> ^Czzz part 2
> exiting
> $
> ```
> 
> that works fine (and is the expected case for `subprocess` calls for
> example in python)

Yeah, I think this is the case I was discussing up above, where the
parent process waits for the subprocess to exit.  If I modify the foo
function in your hook to also have a "sleep 10", then the parent process
hangs until the child process exits, which again would mean that Git
would hang indefinitely if the hook hung.

Can you maybe tell us a little more about your use case?  What are you
doing in your hook that makes this case come up?  Why is your hook
trapping SIGINT?
-- 
brian m. carlson: Houston, Texas, US
OpenPGP: https://keybase.io/bk2204

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