osu-lazer-bin: add derivation for Tachyon releases

[ItsShamed]

Closes #263
Addresses #261

A bit overengineered, but this ensures that both release streams are properly updated, and only when necessary.

[fufexan]

LGTM! Nice work

[ItsShamed]

Maybe worth noting that this would probably need a follow-up once ppy/osu#33575 gets merged.

[Luk45135]

Doesn't this package assumes that both release streams will have the same dependencies all the time and will have to involve extra logic if lazer uses SDL2 and tachyon uses SDL3 for example. Or did i understand something wrong?

[ItsShamed]

We could technically bundle both SDL2 and SDL3 since for now you can switch between them with an envar. Should not be that hard, just an additional build input and path symlink at install should normally do the trick.

It's unlikely that osu! will drastically change dependencies very often, if that ever occurs, this should be handled on a case by case basis.

The discrepancy between both release streams will probably not last long enough to the point where the current state of the derivation will be a pain to maintain.

[smoogipoo]

Does this package replace our included libraries with system-wide ones? osu! intentionally statically links every dependency we need, so I'm curious why this is being done.

In the past, we have applied fixes for ffmpeg4, and rejected other "official-like" releases from using system-wide/shared SDL2 libs due to issues users had with incompatible libraries. We've also used our fork of SDL2 for a period of time during which we had upstream fixes pending.

I notice the same is being done with SDL3 above, which is even more "unstable" than SDL2 given it is the development target.

[smoogipoo]

Furthermore, I don't know about setting COMPlus_GCGen0MaxBudget "600000", and especially what its effects will have on "Satori" (the new GC) on the Tachyon release or even the next Lazer release which will enable it by default on all installs.

There is a reason we removed this flag in ppy/osu-deploy#164

Should I be making individual issues for these? I just looked at the files in this PR and was pretty shocked seeing how far this is being taken.

[fufexan]

@smoogipoo I don't remember the specifics of why we're replacing libraries, nor have I known about the removal of the COMPlus flag. Looking at the "official" osu-lazer-bin derivation in Nixpkgs, it seems what we set may be redundant or even detrimental, as you've said.

I'll make a PR to clean everything up, ensuring no library replacement.

Thanks for the heads-up.