Unwanted system libraries in custom vim Formula

[PatTheMav]

Ever since Homebrew removed configurable Formulas I've been running a custom tap that adds back this functionality and for macOS this works absolutely fine.

Recently my test-bot workflow on Linux always fail with the following error for vim:

==> brew linkage --test patthemav/custom/vim-custom
==> FAILED
Unwanted system libraries:
  /lib/x86_64-linux-gnu/libselinux.so.1

My vim-custom formula is based on the original vim formula before optional features were deprecated and kept up with the changes to the official formula. While the macOS workflow finishes without issues, the Linux workflow acts up.

I have a hunch that I might be missing a dependency on Linux that would otherwise be installed by either Ruby, Perl, Python or Lua (which are not optional in the default formula) and results in vim be linked against system-provided libselinux.

As I have no experience with Linuxbrew except for the brew-bot workflow runs, I'd love to hear suggestions how to fix this (e.g. adding a Linux-only dependency).

[tlk]

Unless you want the formula to work on linux, consider disabling the test in .github/workflows/tests.yml:

-        os: [ubuntu-latest, macOS-latest]
+        os: [macOS-latest]

[PatTheMav]

Yeah that'd my "last resort" option to avoid merging PRs with failed jobs. Right now I'd still like it to work with the templates generated by brew itself and better understand where that unwanted linked library might come from.

[tlk]

I'm not an expert, but maybe libselinux.so.1 needs to be added to SYSTEM_LIBRARY_ALLOWLIST: https://github.com/Homebrew/brew/blob/master/Library/Homebrew/extend/os/linux/linkage_checker.rb

See also https://github.com/Homebrew/brew/blob/master/Library/Homebrew/linkage_checker.rb#L48

[tlk]

Hmm, perhaps the ubuntu-latest image has changed recently?

Selinux in github virtual environments was mentioned in this issue that was closed five days ago:
actions/runner-images#2307

Selinux was mentioned in this formula update three days ago:
Homebrew/homebrew-core#70421

I just checked and libselinux.so.1 is present today on the ubuntu-latest virtual environment:
https://github.com/tlk/github-actions-ubuntu-selinux/runs/1850469673

libselinux1/bionic,now 2.7-2build2 amd64 [installed,automatic]

[PatTheMav]

Interesting - fwiw I also had brew-bot complain about lots of other "unwanted" libraries before which was fixed by removing the optional x11 integration. I haven't dug too deep into this, but it seems that brew-bot builds with all optional dependencies enabled maybe?

[carlocab]

You could try passing a --without-selinux flag to ./configure.

[PatTheMav]

Yep I've discovered that flag in the configure script as well, probably the easiest way to fix this. I wonder if this happens with the official Formula as well or if it just isn't tested/automatically discovered at this time.

[PatTheMav]

Quick update: I updated my vim formula today and added the --without-selinux flag on Linux, but brew linkage still fails and complains about it.

[danielnachun]

Try --disable-selinux instead. From https://github.com/vim/vim/blob/7d41410a455ba62128655beb91c35d3fba299287/src/configure.ac#L478

[PatTheMav]

Of course.. 🤦🏻‍♂️

[danielnachun]

I had to do this for a bunch of formula to make them build on Linux and it was a complete coin toss whether it would be --without-selinux or --disable-selinux. Not sure why developers couldn't be more consistent for this but it's super annoying!

[PatTheMav]

Thanks, that did the trick.

[thiagogenez]

Many thanks for the flag --disable-selinux. It worked here. I hit this error a few days ago and it was annoying.

[danielnachun]

If you find any formulae which need this to be added feel free to make a PR. I was able to catch a lot of them when I first set up Homebrew on CentOS, but there are probably still packages out there which need it and it can be very difficult to track down.

[thiagogenez]

Thanks, @danielnachun. I have recently set up Homebrew on Centos because of the working environment. Happy to contribute to investigating these issues as soon as I catch them, and make a PR to fixing it on CentOS.