MCP gives error when I attempt to decompile it (1.8.8) - minecraft

Question

I'm trying to create my MCP workspace, however, I run into a problem when I run decompile.sh (creates all files). When I run the sh file, it gives me a python error.
Traceback (most recent call last):
File "runtime/decompile.py", line 58, in decompile
commands = Commands(conffile, verify=True, no_patch=no_patch, workdir=workdir, json=json)
File "/Users/louie/Desktop/louie/mcp918/runtime/commands.py", line 176, in __init__
normalStart = self.readconf(workdir, json)
File "/Users/louie/Desktop/louie/mcp918/runtime/commands.py", line 565, in readconf
self.mcLibraries = MinecraftDiscovery.getLibraries(mcDir, self.jsonFile, osKeyword)
File "/Users/louie/Desktop/louie/mcp918/runtime/MinecraftDiscovery.py", line 157, in getLibraries
libFilename = "%s-%s-%s.jar"%(libSubdir, libVersion, substitueString(library['natives'][osKeyword]))
File "/Users/louie/Desktop/louie/mcp918/runtime/MinecraftDiscovery.py", line 185, in substitueString
str = str.replace("${arch}", getArch())
TypeError: coercing to Unicode: need string or buffer, NoneType found
louie#Louies-MBP mcp918 %
Any idea of how to fix this?
OS: Mac
I have python 3 installed
I have java 8 installed

Answer 1

Here's the failing code:
def getArch():
machine = platform.machine()
if os.name == 'nt' and sys.version_info[:2] < (2,7):
machine = os.environ.get("PROCESSOR_ARCHITEW6432", os.environ.get('PROCESSOR_ARCHITECTURE', ''))
machine2bits = {'AMD64': '64', 'x86_64': '64', 'i386': '32', 'x86': '32'}
return machine2bits.get(machine, None)
def substitueString(str):
str = str.replace("${arch}", getArch())
return str
Since you're on an Apple Silicon Mac, you're on the ARM architecture, which MCP918 doesn't support. (This shouldn't be a surprise, since Apple Silicon wasn't released until 5 years after MCP918 was.)