Migrate to linker

[Gerg-L]

I've created:
https://github.com/Gerg-L/linker

Which should be able to replace tmpfiles, and more

It should be able to handle file "activation" and "deactivation"

Currently the biggest parts missing is testing and documentation

It can:

• Create symlinks, files, directories
• Change permissions of created directories and files
• Recursively symlink directories
• Delete files
• Backup or move conflicting files
  And then reverse everything on deactivation

[eclairevoyant]

I have a speculative PR https://github.com/feel-co/hjem/pull/9/files

My intent was originally to put it under <system profile path>/hjem/manifest.json, so that we can derive an absolute path that is tied to the generation when needing to use some linker. (This can easily be done with system.extraSystemBuilderCmds.)

The API I have in mind is to basically provide the paths to the old (/run/current-system/hjem/manifest.json) and new (${config.system.build.toplevel}/hjem/manifest.json) manifests , and the linker program will diff those two JSON files and operate on those. Would that be possible with your design?

[Gerg-L]

A diffing mechanism could be implemented, it would be fairly simple, it might also allow atomic symlink switching

[atagen]

are there still plans to support a drop-in custom linker? I have some work done on one with configurable partial mutability (although it's turning out quite slow as the problem is hard). I would want to be able to use that for certain files and then defer to tmpfiles/this project/some other linker if possible.

[eclairevoyant]

Yes.