x/build: add "slowbots" support

[bradfitz]

We aim to make TryBots be only 5 minutes, but sometimes people want long, deeper tests over all architectures.

We've heard from the compiler/runtime team (@martisch, et al) that a more broad TryBot mode would be useful.

I thought we had a bug for this already but can't find it. (Maybe it was a comment on another bug)

The plan I thought writing about elsewhere was that when clicking "+1 TryBot", you could write some magic syntax in the comment field on Gerrit to specify which extra bots run. Some other tool can help you construct that magic comment & do the Gerrit comment for you, like git-codereview does (when you specify git-codereview mail -trybot)

[bradfitz]

Related:

• x/build: trybots should rebase when testing #9858: x/build: trybots should rebase when testing Builders
• x/build: submit queue, possibly implemented as optional auto-submit on +2 when trybots/slowbots with rebase pass #12482 x/build: optional auto-submit on +2 when trybots (with rebase) pass

[martisch]

Related:

• x/build: trybots should include all platforms that can contribute release-blockers #29239 x/build: trybots should include all platforms that can contribute release-blockers

[bcmills]

Also related:

• x/build: run full codegen testsuite (-all_codegen) on amd64 trybots #34297 (codegen trybots)

[bcmills]

Heh, @bradfitz used the term “SlowBots” in #29239 (comment) too.

[eliasnaur]

This would be fantastic for testing changes on the slow and difficult to set up mobile devices. It would have helped avoid the 4 part fix https://go-review.googlesource.com/c/go/+/193847/

[andybons]

Maybe we fold this into an umbrella issue for a Commit Queue that would cover a lot of the issues above?

[bradfitz]

Let's not. They're different enough and I was actually working on this one last week.

[gopherbot]

Change https://golang.org/cl/201204 mentions this issue: maintner/maintnerd: return TRY= comment directives in Run-TryBot votes

[gopherbot]

Change https://golang.org/cl/201338 mentions this issue: cmd/coordinator: add SlowBots support, opt-in to different slow trybots

[bradfitz]

It's alive! (on https://go-review.googlesource.com/c/go/+/171822/22#message-1627ac4750a897104245e2dc87cc20f838c0b057)

/cc @ianlancetaylor