I use home-manager in a NixOS configuration. When I do nixos-rebuild switch --flake, I frequently get these:
Existing file '/home/icyrockcom/.config/gtk-4.0/gtk.css' is in the way of '/nix/store/rxcgimxlbcn1ngyl86v1ylsyzmpd21fk-home-manager-files/.config/gtk-4.0/gtk.css'
Doing rm /home/icyrockcom/.config/gtk-4.0/gtk.css and re-doing nixos-rebuild switch --flake fixes.
Is there a way to tell home-manager to overwrite a certain file (or anything under a certain folder) always?
You can tell it to always use the -b flag: Appendix B. NixOS Configuration Options
A more proper solution would be to find out which application is overwriting this file after installation and making it not do that.
Ah, got it, that’s the equivalent of the suggested -b command line option.
There’s no way to apply this on a per-file basis? I.e. if there are two files that home-manager manages, I may care about one file not being changed (and the rebuild failing in this case) and not care about the other file (and the rebuild making a backup and putting the new file there instead).
For example, I may care about my ~/.bashrc and not want that silently backed up + overwritten if it gets changed for whatever reason. On the other hand, I don’t really care about the above ~/.config/gtk-4.0/gtk.css.
Not really to my knowledge. Maybe there’s appetite for adding that as a feature upstream?
Alternatives are fixing the problem, or perhaps deleting that file in an activation snippet.
Certain home manager modules do have an effectively per-file “force” flag, like programs.firefox.profiles.<name>.containersForce and programs.firefox.profiles.<name>.search.force.
It’s important to note that the control here is inverted – it’s coming from the program and not the file.
Per-file implementation could theoretically be done like in this commit that implements Firefox container file overwriting.