Cannot build (...is explicitly required in go.mod, but not marked as explicit in..)

Dear all,

I maintain the gitlab package for FreeBSD and wanted to also package gitlab-kas for it. But I'm not able to build it.

I see error messages like:

go build \
	-tags "tracer_static,tracer_static_jaeger" \
	-ldflags "-X gitlab.com/gitlab-org/cluster-integration/gitlab-agent/cmd.Version="v0.0.0" -X gitlab.com/gitlab-org/cluster-integration/gitlab-agent/cmd.Commit=" \
	-o "" ./cmd/kas
go: inconsistent vendoring in /wrkdirs/usr/ports/net/gitlab-agent/work/gitlab-agent-6c1bad9c114ba627d8a2edc6958939d8cf9b4fb4-6c1bad9c114ba627d8a2edc6958939d8cf9b4fb4:
	cloud.google.com/go@v0.70.0: is explicitly required in go.mod, but not marked as explicit in vendor/modules.txt
	github.com/FZambia/sentinel@v1.1.0: is explicitly required in go.mod, but not marked as explicit in vendor/modules.txt
...
run 'go mod vendor' to sync, or use -mod=mod or -mod=readonly to ignore the vendor directory
gmake[1]: *** [Makefile:224: kas] Error 1

The full log can be found here: https://pkg.fechner.net/data/122amd64-gitlab/2020-12-15_11h58m30s/logs/errors/gitlab-agent-13.7.0.log

It seems that there some files are not in sync?

I'm not sure if this is a problem in gitlab-kas or in how I try to package it. Maybe you can help here?

Thanks a lot!