When you're trying to figure out what shader some NIR pass broke, use
nir_shader_bisect_select() to decide between NIR pass behaviors, and then
nir_shader_bisect.py will help you automatically bisect down to which
source_blake3 is at fault. Once it's identified, it prints you a C call
you can use for selecting that shader specifically, which you can use for
continuing on in your debugging.
On a test I was looking at, this took 10 steps to bisect 134 shaders down
to the source_blake3 of the NIR shader in question.
This idea is heavily lifted from Job Noorman's ir3_shader_bisect.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37468>