Not related to your question at all, but:
I don’t recommend editing the source code from cargo’s files. Instead, the correct way to modify a dependency would be making a fork and using it as a gift dependency (or path dependency, which is even easier).
This entire post is so ignorant it can be summed up in a one paragraph analogy:
“Why do everyone love screwdrivers so much? I drove in nails perfectly with my hammer, but the screwdrivers are so bad at it! Who even designed them? What a horrible design!”