Re: [PATCH] .gitignore: ignore temporary files from 'bear'

[Brendan Jackman <jackmanb@google.com>]

On Sat Aug 30, 2025 at 7:25 PM UTC, Nicolas Schier wrote:
> On Fri, Aug 29, 2025 at 04:38:24PM -0700, Nathan Chancellor wrote:
>> Hi Brendan,
>> 
>> On Wed, Aug 27, 2025 at 08:59:43AM +0000, Brendan Jackman wrote:
>> > Bear [0] is a tool for generating compile_commands.json. For Kbuild,
>> > Bear is not useful, since Kbuild already generates the necessary info
>> > and that can be converted to compile_commands.json by
>> > gen_compile_commads.py.
>> > 
>> > However, for code in tools/, it's handy. For example, this command
>> > updates compile_commands.json so that clangd code navigation will also
>> > work for the VMA unit tests:
>> > 
>> > 	bear --append -- make -C tools/testing/vma -j
>> > 
>> > Bear generates some temporary files. These are usually deleted again
>> > but having them show up ephemerally confuses tools that trigger
>> > recompilation on source code changes. Ignore them in Git so that these
>> > tools can tell they aren't source code.
>> > 
>> > [0]: https://github.com/rizsotto/Bear
>> > 
>> > Signed-off-by: Brendan Jackman <jackmanb@google.com>
>> 
>> We can likely take this via the Kbuild tree. I do wonder if this would
>> be better in a tools/.gitignore file since bear is really only of use
>> there but I am not sure it matters much.
>
> yeah, please consider using tools/.gitignore.  

I don't believe that works here, because AFAIK clangd assumes a single
compile_commands.json, so while we could git-ignore
tools/compile_commands.json that wouldn't really serve the usecase I
have here with 'bear --append'.

> Please have a look at
> this thread about ignoring files from "external" tools:
>
> https://lore.kernel.org/lkml/CAHk-=wiJHMje8cpiTajqrLrM23wZK0SWetuK1Bd67c0OGM_BzQ@mail.gmail.com/

Hm, I would read the spirit of that thread as not being about things
from 'external tools', rather Linus' objection seems to be that the
_lifetime_ of the mbox files is unrelated to the kernel build. Well, to
be honest the only coherent principle I can get from it is "don't break
Linus' workflow". Which... yeah, is still a pretty valid concern.

> If using tools/.gitignore is not possible, I think the best way for
> ignoring files that are not natively related to kernel build tools is to 
> update the local ~/.config/git/ignore, as suggested in
>
> https://lore.kernel.org/lkml/CAK7LNAQas0cK7pgi72tYC3yU=ZkQxnr41YYW1mXd-sWiHtG+UA@mail.gmail.com/

Given this alternative, and given the fact that I'm ignoring a very
generic suffix in *.tmp (if it was just *.events.json I'd say the
practical risk has gotta be close to nil), I think we could just drop
this unless anyone else pops up with evidence that 'bear' is important
to lots of people or something.

Cheers,
Brendan