Cargo build hangs with " Blocking waiting for file lock on the registry index" after building parity from source

I followed the readme instructions for building Parity from source and then executed:
cargo build --release
~/.cargo/bin/cargo build --release


as instructed, both of which returned the following message while the prompt hung:

Blocking waiting for file lock on the registry index

I'm on a Mac.

I suggest looking at 'Cargo build hangs with " Blocking waiting for file lock on the registry index" after building parity from source' first.

I had the same issue and had success with a quick and dirty

rm -rf ~/.cargo/registry/index/* ~/.cargo/.package-cache

Stack Overflow Q#47565203, score: 279