xbstrap: add `discard` command for nuking packages

[no92]

[ArsenArsen]

Why change the meaning of mark_* instead of just removing the source and build directories (especially since this might lead to conflicts of some sort)?

Also, what scenario is this necessary in that isn't better addressed otherwise?

[no92]

Addressed the issues raised above.

[Dennisbonke]

Bump.

[ArsenArsen]

my question remains unadressed

[no92]

Also, what scenario is this necessary in that isn't better addressed otherwise?

I use this to clean up sources I don't need (e.g. before pulling from CI), e.g. after upstreaming them. Also, testing patches is really convenient. Manually removing risks leaving parts of the package behind, which this would avoid. Finally, providing a way to delete packages is, to me, the natural counterpart to being able to build/pull them.

[ikbenlike]

personally I feel a command like this is useful - I have ran into cases where I want to purge a package locally, and having to go in with a separate tool (even if just rm/rmdir) to do so feels like an oversight in the user experience of xbstrap, even more so because this functionality is seemingly trivial to implement

[ArsenArsen]

again, an uninstall command would be very useful. the delete-source action here also seems unobjectionable, even though I don't see how it's any better than removing source directories you work in manually anyway, however, the discard-pkg action does not discard pkgs (it uninstalls, but deletes build, but doesn't delete artifacts), hence it is not really acceptable in its current form