In switching from Windows PowerShell to Git Bash, I ran into this error:

gpg: keyblock resource 'c:/Users/Dev1/.gnupg\secring.gpg': file open error
gpg: keyblock resource 'c:/Users/Dev1/.gnupg\pubring.gpg': file open error
gpg: skipped "0x6af2bf57992f19ed": secret key not available
gpg: signing failed: secret key not available
error: gpg failed to sign the data
error: unable to sign the tag

0x6af2bf57992f19ed refers to my PGP key and BASH is not able to find it. PowerShell never has this problem, so apparently PowerShell searches the HOME directory and finds the GPG files in C:/Users/Dev1/AppData/Roaming/gnupg instead.

To setup the path for BASH, just assign and export GNUPGHOME to whatever it needs to be:

$ export GNUPGHOME="/c/Users/Dev1/AppData/Roaming/gnupg"

There you go!