Also because if I dev Snappy.jl to allow snappy_jll 1.1.9 and dev Parquet to allow Snappy 0.4.0, then tests of both Snappy and Parquet are successful for me on M1:
Testing Running tests...
Test Summary: | Pass Total Time
parquet tests | 3910 3910 21.3s
Testing Parquet tests passed
[...]
Testing Running tests...
Test Summary: | Pass Total Time
Low-level Interfaces | 54 54 0.1s
Test Summary: | Pass Total Time
High-level Interfaces | 113 113 0.7s
Testing Snappy tests passed
So I have no idea what was so catastrophically wrong.