Plan:

1. Show the problem with a timeout by reverting to not ultraslowtest rather than not slowtest:

   • Timed out @ 75% complete in 1h 5m 43s on 43256dd / 2.0.0.dev0+466.gc143f7b93 (OpenBLAS 0.3.23 with 1 thread)
   • np.show_config (in the _infos.sh step) has no Supported SIMD extensions section.

2. Try the 1.25.1 wheel from PyPI:

   • Completed in 1h 1m 30s on ac99726 / 1.25.1 (OpenBLAS 0.3.23 with 1 thread)

   • 77% complete in ~43m (manual inspection)

   • np.show_config in the _infos.sh step says:

     Supported SIMD extensions in this NumPy install:
         baseline = SSE,SSE2,SSE3
         found = SSSE3,SSE41,POPCNT,SSE42,AVX,F16C,FMA3,AVX2
         not found = AVX512F,AVX512CD,AVX512_KNL,AVX512_KNM,AVX512_SKX,AVX512_CLX,AVX512_CNL,AVX512_ICL
     

3. Try the 1.25.0rc1 wheel from scientific-python-nightly-wheels

   • Completed in 52m 40s on 3e2a5fc / 1.25.0rc1+218.g0e5a362fd (OpenBLAS 0.3.23 with 1 thread)

   • 76% complete in ~36m (manual inspection)

   • np.show_config (in the _infos.sh step) says:

     Supported SIMD extensions in this NumPy install:
         baseline = SSE,SSE2,SSE3
         found = SSSE3,SSE41,POPCNT,SSE42,AVX,F16C,FMA3,AVX2
         not found = AVX512F,AVX512CD,AVX512_KNL,AVX512_KNM,AVX512_SKX,AVX512_CLX,AVX512_CNL,AVX512_ICL
     

(2) and (3) being faster than (1) will help isolate the time frame of changes and ensure it's not an issue with all SPNW wheels. Looks like the 1.25 RC wheel up here was ~23 days ago, so not an awesome bisect but at least a start.