all: use the (experimental) Zig package manager

[slimsag]

This is a tracking issue for adopting the new experimental Zig package manager. Also see #719 which will help this effort.

Major Zig issues

1. package manager cannot download large tar archives, like the Dawn sources or even this 3.3MB tar file:
   • Solution: std.tar: support pax headers and gnu_long{name,link} ziglang/zig#15382
2. file exists in multiple modules - you cant have 2 modules (freetype and harfbuzz) depend on a common module (brotli) yet, because the package manager believes they're the same module so it thinks they're duplicate.
   • Solution: Deduplicate uses of the same package across dependencies ziglang/zig#15407
3. error: EndOfStream when using build.zig.zon in the main repo to depend on a pure-Zig dependency
   • SOLUTION: std.http: do -> wait, fix redirects and uaf ziglang/zig#15445

Minor Zig issues

Things we have workarounds for, or have accepted for now.

1. package manager use case: a Zig module can express it needs to be linked against a C library artifact ziglang/zig#16206
   • Solution: Add CompileStep APIs to Build.Module. ziglang/zig#14731
   • Workaround: we have one
2. No way to fetch/use a binary version of Dawn by default
   • Solution: @mlugg is reworking Zig modules a bit; "say you wanted to have a binary dependency on a package containing libepic.a. what you'd have is a package containing a build.zig and a libepic.a, and the build.zig sets up and exposes one module, with that module containing libepic.a through addObjectFile (which should be renamed or expanded)"
3. No support for optional dependencies; which will mean users must download the Dawn source dependency which is large/wasteful
   • Solution: none yet

Mach blockers

4. Begin using mach-gamemode in the main repo
5. https://github.com/hexops/glfw/blob/master/build.zig.zon references commits that do not exist in the repo
6. Begin using mach-dusk in the main repo
7. Begin using mach-sysjs in the main repo
8. Begin using mach-ecs in the main repo
9. Begin using mach-earcut in the main repo
10. Merge pending ECS changes
11. Support latest Zig version; Swap step.install() with b.installArtifact(step);

Migration status by project

• https://github.com/hexops/mach-core
• https://github.com/hexops/mach-gpu
• https://github.com/hexops/mach-gpu-dawn
  • package with Zig dawn#12
• https://github.com/hexops/mach-freetype
  • Open PR port to zig package manager mach-freetype#1
  • Blocked on Add CompileStep APIs to Build.Module. ziglang/zig#14731
• https://github.com/hexops/mach-glfw
  • Open PR use package manager mach-glfw#2
  • Blocked on Add CompileStep APIs to Build.Module. ziglang/zig#14731
• https://github.com/hexops/mach-sysaudio
  • Open PR Port to package manager mach-sysaudio#1
  • Works on Windows/Linux, blocked on Add CompileStep APIs to Build.Module. ziglang/zig#14731
• https://github.com/hexops/mach-basisu
  • Open PR: Use package manager mach-basisu#1
  • Blocked on Add CompileStep APIs to Build.Module. ziglang/zig#14731
• https://github.com/hexops/mach-model3d
  • Open PR Port to Zig package manager mach-model3d#1
  • Blocked on Add CompileStep APIs to Build.Module. ziglang/zig#14731
• https://github.com/hexops/mach-ecs
  • Port to package manager mach-ecs#1
• https://github.com/hexops/mach-sysjs
  • Port to Zig package manager mach-sysjs#1
• https://github.com/hexops/mach-dusk
  • Port to package manager mach-sysgpu#1
• https://github.com/hexops/mach-earcut
  • Port to package manager slimsag/mach-earcut#1
• https://github.com/hexops/mach-gamemode
  • Port to Zig and package manager mach-gamemode#1

[slimsag]

We are nearly fully on the package manager now; though there are some follow-ups to be had: https://github.com/hexops/mach/issues?q=is%3Aissue+is%3Aopen+label%3Apackage-manager