On Mon, Aug 27, 2018 at 04:23:34PM -0700, Stas Bekman wrote:
> I'm debugging the workings of a configured git content filter
> (nbstripout) and I'm trying to get GIT_TRACE to show me the files it's
> operating on, but it doesn't. Consider:
>
> $ GIT_TRACE=1 git pull origin master
> [...] removed irrelevant sections of the output
> 16:49:28.846707 run-command.c:640 trace: run_command: git merge
> FETCH_HEAD
> 16:49:28.849309 git.c:344 trace: built-in: git merge
> FETCH_HEAD
> Updating 1ea49ad..ae0ba93
> 16:49:28.863291 run-command.c:640 trace: run_command: nbstripout
> 16:49:28.864700 run-command.c:640 trace: run_command: nbstripout
> 16:49:28.866060 run-command.c:640 trace: run_command: nbstripout
> [...] many more of the same
>
> How can I get GIT_TRACE's run_command to show the arguments passed to
> the filter? I looked at various other debug environment variables in
> git's manual, but I don't see anything that would enable that level of
> debug.
GIT_TRACE should always show the arguments. But unless you specify
arguments in the clean/smudge filter config, then Git won't pass any.
The stdin/stdout stream is all that matters.
So e.g.:
$ echo '* filter=foo' >.gitattributes
$ git config filter.foo.clean 'myfilter'
$ GIT_TRACE=1 git add .
19:42:16.516401 [pid=14112] git.c:415 trace: built-in: git add .
19:42:16.517454 [pid=14112] run-command.c:637 trace: run_command: myfilter
$ git config filter.foo.clean 'myfilter --foo'
$ touch .gitattributes ;# make sure we actually read it again ;)
$ GIT_TRACE=1 git add .
19:42:58.122942 [pid=14156] git.c:415 trace: built-in: git add .
19:42:58.124023 [pid=14156] run-command.c:637 trace: run_command:
'myfilter --foo'
You can use "%f" to pass the name of the file, like:
$ git config filter.foo.clean 'myfilter %f'
$ touch .gitattributes
$ GIT_TRACE=1 git add .
19:44:51.187177 [pid=14318] git.c:415 trace: built-in: git add .
19:44:51.188256 [pid=14318] run-command.c:637 trace: run_command:
'myfilter '\''.gitattributes'\'''
Of course that won't be helpful if your filter actually respects the
argument. For a "clean" filter that might be OK (e.g., if it just tells
your filter to read from the filesystem instead of stdin), but it's
almost certainly not what you want for a "smudge" filter.
You can work around it with some shell hackery:
git config filter.foo.clean 'f() { echo >&2 "cleaning $1"; myfilter ...; }; f
%f'
and then even without GIT_TRACE, you get:
$ git add .
cleaning .gitattributes
Or if you really just want to trigger for GIT_TRACE, try just this:
$ git config filter.foo.clean 'f() { myfilter; }; f %f'
19:52:52.874064 [pid=14719] git.c:415 trace: built-in: git add .
19:52:52.875115 [pid=14719] run-command.c:637 trace: run_command: 'f() {
myfilter; }; f '\''.gitattributes'\'''
There you get the name in the trace output, but the invoked command
doesn't actually do anything with it.
-Peff
