[WIP] LLVM 20 llvmdev recipe

[gmarkall]

Using this PR for development / notes.

Build / installation

I built for linux-64 with the GHA builder (https://github.com/numba/llvmlite/actions/runs/15325329108)

Installation requires:

  + liblzma-devel    5.8.1  hb9d3cd8_1          conda-forge                             442kB
  + xz-gpl-tools     5.8.1  hbcc6ac9_1          conda-forge                              34kB
  + xz-tools         5.8.1  hb9d3cd8_1          conda-forge                              96kB
  + libstdcxx-ng    15.1.0  h4852527_2          conda-forge                            Cached
  + zlib            1.2.13  h4ab18f5_6          conda-forge                            Cached
  + xz               5.8.1  hbcc6ac9_1          conda-forge                              24kB
  + zstd             1.5.6  ha6fb4c9_0          conda-forge                            Cached
  + llvmdev         20.1.5  hfc4b9b4_0          /home/gmarkall/numbadev/llvmdev-20      684MB

• Re-enable assertions: See Missing LLVM assertions in Linux build breaks debug output #1194
• Don't have zlib / zstd dependencies for wheels
• Root cause segfault

[gmarkall]

Are the zlib and zstd dependencies a problem?

Yes, for wheels. Different recipe versions may be needed for wheels and conda packages.

[seibert]

I think #1227 should fix the issue you saw when you ran the build with GitHub Actions. You might need to merge main into this branch to pick up the fix.

[gmarkall]

Thanks, will give it a try!

[stuartarchibald]

As noted in OOB discussion, this patch needs to re-enable building with assertions "on" for the purposes of Numba channel releases/development builds.

Further, I'm not sure whether this needs to build with RTTI, I recall historically that it was "off" but it seems to have been set to "on" recently.

[esc]

Looks like the wheel builds are failing with:

Applying patch: /root/llvmlite/conda-recipes/llvmdev_for_wheel/../llvm15-clear-gotoffsetmap.patch
Applying patch: /root/llvmlite/conda-recipes/llvmdev_for_wheel/../llvm15-clear-gotoffsetmap.patch with args:
['-Np1', '-i', '/tmp/tmpmw4obdaz/llvm15-clear-gotoffsetmap.patch.native', '--binary']
Warning: failed to download source.  If building, will try again after downloading recipe dependencies.
Error was: 
Command '['/root/miniconda3/envs/buildenv/bin/patch', '--no-backup-if-mismatch', '--batch', '-Np1', '-i', '/tmp/tmpmw4obdaz/llvm15-clear-gotoffsetmap.patch.native', '--binary', '--dry-run']' returned non-zero exit status 1.

and so far none of the builds have succeeded yet, they have all failed in one capacity or another.

As a first step I would suggest to remove the llvm15 patch application and then track down the rest of the issues.

[esc]

A few llvmdevs have built fine:

• linux-64
• linux-aarch64
• win-64

[esc]

The PR #1259 was included here via a merge to main. The PR #1262 was also included, but merged directly with this branch.

It looks promising now, no llvmdev runs have failed and we are only waiting on osx-64 and win64.

💪 💪 💪

[esc]

Waiting on successful "Numba with LLVM 20 enabled llvmlite"-test.

[esc]

Based on the tests in: #1092 and numba/numba#10146 -- this is now ready to merge!