Fish:

$ set -x GPG_TTY (tty)

Bash:

$ export GPG_TTY=$(tty)

This will tag and sign a release via GPG:

$ git tag -s v0.9.4 -m "Release v0.9.4"

…the signature can be verified if you have the proper public key in your GPG keyring with:

$ git tag -v v0.9.4

You can see a tagged release with:

$ git show v0.9.4

Push your annotated tags to the remote repo with:

$ git push –-tags