importrandomrandom.seed(0)importzlibimportbinasciidefchunks(list,n):foriinrange(0,len(list),n):yieldlist[i:i+n]random_megabyte=random.randbytes(1024*1024)random_1_gigabyte=random_megabyte*1024*1random_4_gigabyte=random_megabyte*1024*4crc_1_gigabyte_zlib=zlib.crc32(random_1_gigabyte,0)crc_1_gigabyte_binascii=binascii.crc32(random_1_gigabyte,0)crc_4_gigabyte_zlib=zlib.crc32(random_4_gigabyte,0)crc_4_gigabyte_binascii=binascii.crc32(random_4_gigabyte,0)# incremental computation in chunks < 2 GB fixes macOS arm64chunked_crc_4_gigabyte_zlib=0chunked_crc_4_gigabyte_binascii=0forchunkinchunks(random_4_gigabyte,1024*1024*1024*1):chunked_crc_4_gigabyte_zlib=zlib.crc32(chunk,chunked_crc_4_gigabyte_zlib)chunked_crc_4_gigabyte_binascii=binascii.crc32(chunk,chunked_crc_4_gigabyte_binascii)print("crc_1_gigabyte_zlib".ljust(32),"expected: 0xe28bc234 computed:",hex(crc_1_gigabyte_zlib))print("crc_1_gigabyte_binascii".ljust(32),"expected: 0xe28bc234 computed:",hex(crc_1_gigabyte_binascii))print("crc_4_gigabyte_zlib".ljust(32),"expected: 0x278432d6 computed:",hex(crc_4_gigabyte_zlib))print("crc_4_gigabyte_binascii".ljust(32),"expected: 0x278432d6 computed:",hex(crc_4_gigabyte_binascii))print("chunked_crc_4_gigabyte_zlib".ljust(32),"expected: 0x278432d6 computed:",hex(chunked_crc_4_gigabyte_zlib))print("chunked_crc_4_gigabyte_binascii".ljust(32),"expected: 0x278432d6 computed:",hex(chunked_crc_4_gigabyte_binascii))

mac-arm64:crc_bug dev_admin$ /opt/homebrew/bin/python3 crc_bug_report.py crc_1_gigabyte_zlib              expected: 0xe28bc234 computed: 0xe28bc234crc_1_gigabyte_binascii          expected: 0xe28bc234 computed: 0xe28bc234crc_4_gigabyte_zlib              expected: 0x278432d6 computed: 0x6b54c6becrc_4_gigabyte_binascii          expected: 0x278432d6 computed: 0x6b54c6bechunked_crc_4_gigabyte_zlib      expected: 0x278432d6 computed: 0x278432d6chunked_crc_4_gigabyte_binascii  expected: 0x278432d6 computed: 0x278432d6