How to get a specific GO_MODULE tag (MODVERSION)

Hello,

I'm trying to get access to a go.mod no tagged that contains fixes that I
need to try.

security/gopass
https://github.com/gopasspw/gopass
and the module that I want to get is from commit
https://github.com/gopasspw/gopass/commit/8c666a93d844015cca992be0ab0c39992bb096ed

I've see some examples of ports doing this like devel/lab:

USES=           go:modules
MODVERSION=     0.25.2-0.20230225220034-98c3f01c08e1
GO_MODULE=      github.com/zaquestion/lab@v${MODVERSION}

My question is: how do I get vX.0.0-yyyymmddhhmmss-abcdefxyz,
especially yyyymmddhhmmss
that it is recomended not be created by hand.

in https://jfrog.com/blog/go-big-with-pseudo-versions-and-gocenter/

Thanks!
-- 
Nuno Teixeira
FreeBSD Committer (ports)