x/build/cmd/release: update to freebsd-{amd64,386}-11_2 builder for 1.15 RC 2+

[dmitshur]

The cmd/release command is currently configured to use the freebsd-{amd64,386}-11_1 builders for the freebsd release targets.

However, we've documented that Go 1.13 onwards requires at least FreeBSD 11.2 (see https://golang.org/doc/go1.13#freebsd):

As announced in the Go 1.12 release notes, Go 1.13 now requires FreeBSD 11.2 or later; support for previous versions has been discontinued. FreeBSD 12.0 or later requires a kernel with the COMPAT_FREEBSD11 option set (this is the default).

The build dashboard is correctly configured not to test Go 1.13+ commits on freebsd-{amd64,386}-11_1 builders. Luckily, the freebsd-amd64-race still uses FreeBSD 11.1 and does run on new Go commits, so we have test coverage from that. We also have test coverage from freebsd-{amd64,386}-11_2 builders, and they're passing. In summary:

• FreeBSD 11.1 and older builders are disabled, no supported Go commits are tested (source).
  • Build status is unknown.
• FreeBSD 11.2 and newer builders are enabled and test supported Go commits (source).
  • Builds are passing.
• freebsd-amd64-race builder uses FreeBSD 11.1 and tests supported Go commits (source).
  • Builds are passing.

It would've been better if we caught and fixed this earlier, but given there will soon be an RC 2, we can fix this now. In the unlikely case the change of builder causes FreeBSD-specific regressions in RC 2 (despite passing builders), we can consider going back to the previous builder. FreeBSD is not a first class port and this change is outside of tree (which is why I'm not asking for a freeze exception), so it seems in scope. I'll apply release-blocker label because the fix is small and we should get it in if we don't learn something new suggesting otherwise. I'll send a CL.

I filed #40561 so we don't forget during future cycles, and do this at a better time.

/cc @golang/osp-team

[gopherbot]

Change https://golang.org/cl/246597 mentions this issue: cmd/release: start using FreeBSD 11.2 builders for Go 1.15 RC 2+

[gopherbot]

Change https://golang.org/cl/246638 mentions this issue: dashboard: re-enable FreeBSD 11.1 builders on Go 1.14 and 1.13

[gopherbot]

Change https://golang.org/cl/246639 mentions this issue: dashboard: remove obsolete disabled builders