Description of problem:
The documentation at https://docs.fedoraproject.org/en-US/packaging-guidelines/Golang/ seems to provide an invalid example in its "Simple binary package" section. Following the example there results in a package specification that produces the following when processed with rpmbuild:

RPM build errors:
    -u use in %forgemeta is deprecated, use -z instead to select a separate set of rpm variables!
    Bad exit status from /tmp/rpm-tmp.rP7edU (%prep)

Indeed, the actual golang-github-boltdb-bolt package has diverged from the example at https://docs.fedoraproject.org/en-US/packaging-guidelines/Golang/.

Version-Release number of selected component (if applicable):
Webpage: Last build: Thu Oct 17 10:00:11 UTC 2019
Build host: Fedora 31

How reproducible:
Every time

Steps to Reproduce:
1. Write an RPM specification based on the "Simple binary package" example at https://docs.fedoraproject.org/en-US/packaging-guidelines/Golang/
2. Run "rpmbuild -ba foo.spec"

Actual results:
-u use in %forgemeta is deprecated, use -z instead to select a separate set of rpm variables!

Expected results:
The package should build.