/usr/local/bin is not writeable by nix-homebrew.user after install

[Cu3PO42]

I've installed Homebrew on a fresh macOS x64 VM. Installing a formulae immediately fails because /usr/local/bin is not writeable by my user. Indeed, it is owned by root, even though most other files in in /usr/local are owned by myuser:admin. The bin and Homebrew folders, however are owned by root:wheel.

I could fix this by inserting an appropriate chown in the setup script, but I'm not 100% sure if that is just a band-aid without fixing the underlying root cause.

Unfortunately I don't currently have access to an aarch64 Mac to test the behaviour there.

[Cu3PO42]

I started looking into this, but have not been able to pinpoint the issue. Here's what I know:

• initialize_prefix fails to set the correct ownership on /usr/local/bin
• Rerunning initialize_prefix does not fix the issue
• Executing the relevant sections manually, /usr/local/bin is added to chowns[@].
• Running the section that executes these modifications, all conditions appear to be met.
• If I replace all utilities (i.e. chown, chgrp, ...) with echo <utility> the necessary commands to change /usr/local/bin's ownership are printed. Manually running them has the desired effect.

I currently cannot explain the inconsisties I've observed.

[Cu3PO42]

Thanks for looking into this! Right now I have a serviceable hot fix for this: I added

  system.activationScripts.extraUserActivation.text = lib.mkOrder 1501 (lib.concatStringsSep "\n" (lib.mapAttrsToList (prefix: d: if d.enable then ''
    sudo chown -R ${config.nix-homebrew.user} ${prefix}/bin
    sudo chgrp -R ${config.nix-homebrew.group} ${prefix}/bin
  '' else "") config.nix-homebrew.prefixes));

to my config, which allows the installation to proceed successfully.