goa-oauth2-1.1.0 is not a library.
Visit the last successful build:
goa-oauth2-1.1.1
goa-oauth2
This utility retrieves OAuth2 tokens from the GNOME Online Accounts service. It's extremely useful for applications like msmtp:
# ...
account gmail
host smtp.gmail.com
from example@gmail.com
user example@gmail.com
passwordeval goa-oauth2 example@gmail.com