On needing to rebuild project target after running :refresh_compile_commands

[brtdylan]

Hey there, just wanting to see if I can gain some understanding about an issue I'm seeing while using this amazing tool with our (fairly complex) codebase

For a while I was seeing spurious in-line compile errors in my editor after generating compile commands. I was going a little mad trying to figure out the root cause, and I realized that if I rebuild a target in our codebase (not yet clear to me if it needs to be the target for which I'm editing src, or any target within our project) after running :refresh_compile_command, everything becomes happy again. So the magic workflow for me seems to be: build our repo to produce any generated files, run :refresh_compile_commands, build something else in our repo (cached, fast).

My best guess as to why that does the trick is that by re-building a relevant target in our repo, the bazel symlink paths are re-established to align with the valid paths that match what the generated compile commands expect. I'm sort of waving my hands though, and my bazel-fu isn't strong enough to understand the full picture here, so I wanted to see if this sounds like anything y'all have come across // sounds expected?

Anyway, I'm super happy everything's working again with this tool, it's truly a life saver! Thank you for continuing to develop and support it 👏

[ashpil]

Experiencing this as well, seems related to #140.

[cpsauer]

Hey, Dylan. Good to hear from you again.

I'm surprised--and would like this tool to not have that behavior if we can make it so. To make sure I'm understanding correctly: Everything's fine, with generated files generated, but then when you re-run this tool, header searching breaks until you run a build again. Is that right?

I wish I knew what was wrong off the top of my head, but I don't; I haven't run into this in our codebase, and on a quick test, I'm seeing generated files hold up across runs of the tool. I totally believe you about the problem and everything, but that means I'm going to need your help tracking it down further. Any pattern in the headers that can't be found? Are the paths to them indeed getting removed from the filesystem on build, and if so what are they? Are they _virtual_includes? There aren't any bazel-bins in your compile_commands.json, are there? (That's the only thing that should change between runs, but we shouldn't be referencing it.) Maybe also comment back your OS, just in case that's relevant. Any other ideas about what might be going on?

Delighted to hear this tool is otherwise so useful to you guys. Still love the seal photo :) Chris

[cpsauer]

Wrote that without having seen your crossref, yet, Andrei, or having read the updates over there. Dylan, could you check that yours are indeed all virtual includes (the bane of this tool lol), and if so, subscribe to #140 and close this so we're all tracking it and working together there?

[cpsauer]

If it is, we'll likely have it resolved soon. I put up a PR over at https://github.com/bazelbuild/bazel/pull/20540 that should fix.

Any amount you'd like to chime in over there to encourage merging would be much appreciated :)

[brtdylan]

Hi Chris, Thanks for following up! And thanks Andrei for pointing out that issue, I believe that's what's at play here as well. The compile errors seem to be mostly around generated protobuf and flatbuffer code, and I'm seeing that many protobuf and flatbuffer files are within a _virtual_includes dir in the compile_commands.json (though not the generated headers themselves, seems more like protobuf src dirs?). I will close this one and follow along there. Awesome to see you were able to root cause already + have a fix up 🥳 I'll close this issue as a dupe of #140 and will try to test it on our repo and follow up there / on your PR

And if you're local to the Bay Area, and haven't done it before, winter time is a great time to see the elephant seals & seal pups around Pt Reyes as they come in to the beaches for pupping season 🦭 : )

[cpsauer]

Likewise! Hopefully they merge it in soon. Thanks for being great.

I am indeed local and have fond childhood memories of going to see :) I also just think seals are cute.

(I'm around Stanford most of the time; if you're ever around and want to say hi, drop me a line. Could be fun to meet up. Just shoot me an email at cpsauer ~at~ cs dot stanford dot edu if so.)

[cpsauer]

And thanks for the support :)

[cpsauer]

The fix has made it into the bazel mainline!

Thanks for helping track this down and get it in--should be released as part of Bazel 7.1 and the next rolling release!