Debugging and test fixes for CI test_compression_br worked on my box under python 3.6. In CI it worked in 3.4 but failed on all other versions 3.6,7,8,9,dev. Error: json_dict = json.loads(b2s(brotli.decompress(f.content))) E brotli.error: BrotliDecompress failed so print f.content. Also restructured the code to not check for type of f.content. Instead try json.loads(f.content) and if we get an exception try decompressing. Use this for br and zstd tests.