On latest master branch right now, the src/vendor directory is not clean. Its contents do not correspond 1:1 to the versions specified by the src/go.mod file.

Following the steps in src/README.vendor results in a non-zero diff:

go $ go version
go version devel +b13ce14c4a Tue Jan 28 20:26:36 2020 +0000 darwin/amd64
go $ cd src
src $ go mod tidy
src $ go mod vendor
src $ git status
On branch master
Your branch is up to date with 'origin/master'.

Changes not staged for commit:
  (use "git add/rm <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	deleted:    vendor/golang.org/x/sys/cpu/cpu_riscv64.go

no changes added to commit (use "git add" and/or "git commit -a")

This is due to recent commits such as CL 216260, CL 216261, CL 216262 that are related to riscv64.

This makes it difficult and error prone to make changes to versions in src/go.mod, because the end result includes unexpected changes. See discussion in CL 216680.

If it's reasonable to resolve this, I don't think we should release Go 1.14 with a vendor directory that isn't clean, so tentatively marking this as release-blocker, but open to discussion.

/cc @4a6f656c @FiloSottile @golang/osp-team