This line arch=("x86_64") results in the following error:

'"' is not one of ['any', 'pentium4', 'i486', 'i686', 'x86_64', 'x86_64_v3', 'arm', 'armv6h', 'armv7h', 'armv8', 'aarch64']

This happens for all Bash arrays. The quotes are recognised as own elements.

license=("MIT") errors with '"' is not one of ['AGPL3', 'Apache', ....

This bug was probably introduced with a fix for #4.