x/build: try a -racegocommand builder

[dmitshur]

Between #77053, #79667, #79680, there may be a remaining data race in the cmd/go/internal/load.PackagesAndErrors implementation. Maybe a builder similar to -racecompile, but one that builds the go command in race mode instead, would be helpful in tracking this down.

CC @golang/release, @golang/command-line.

[dmitshur]

Sent crrev.com/c/7892066 and go.dev/cl/785920.

[gopherbot]

Change https://go.dev/cl/785920 mentions this issue: main.star: add a linux-amd64-racegocommand-noopt builder at tip

[gabyhelp]

Related Issues

• build: run race-enabled toolchain #19962
• cmd/dist: run cmd tests in race mode #37940 (closed)
• x/build: add a longtest+race builder #54630 (closed)
• cmd/compile: racecompile builder failures on multiple packages #28170 (closed)
• x/build/cmd/racebuild: migrate to LUCI #72767 (closed)
• x/build: add darwin-race builder #17674 (closed)
• x/build: LUCI builders fail to find C compiler #65483 (closed)
• x/build/env/linux-arm64: add race builder for linux/arm64 #28637 (closed)
• go/types: data race in x/tools -race builders #44434 (closed)
• cmd/go/internal/work: data race in builder.Showcmd #64010 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[gopherbot]

Change https://go.dev/cl/789380 mentions this issue: main.star: add a linux-amd64-racegocommand builder at tip

[dmitshur]

Both the -racegocommand and -racegocommand-noopt builders have been running for some time, and so far they haven't uncovered interesting races in the go command. Issue #79667 turned out to be a problem in the runtime and has been resolved by now.

I think the next step here is to stop the -racegocommand-noopt builder at least, and maybe let -racegocommand run longer or eventually stop it too if it doesn't provide much useful signal.