Change https://golang.org/cl/204038 mentions this issue: dashboard: skip reboot test on ppc64x builders

Can the test be modified to print out more information about the failure?
Maybe stderr has more information.

It's already redirecting stdout and stderr to its own stdout/stderr:

        cmd := exec.Command(filepath.Join(runtime.GOROOT(), "src", makeScript))
        cmd.Dir = gorootSrc
	cmd.Env = append(os.Environ(), "GOROOT=", "GOROOT_BOOTSTRAP="+runtime.GOROOT())
        cmd.Stderr = os.Stderr
        cmd.Stdout = os.Stdout
        if err := cmd.Run(); err != nil {
                t.Fatal(err)
        }

So right above the "Exit status 2" is how it failed, the lines that @bcmills quoted.

Not sure why reboot would take more memory, though. It already did a make.bash successfully if we made it this far, and dist itself doesn't take much memory.

Oh---- rundockerbuildlet gives it a tmpfs as its /workdir:

https://github.com/golang/build/blob/c53d4ba783d113c1e97ca07be915b7e2f6142ede/cmd/rundockerbuildlet/rundockerbuildlet.go#L157

And reboot runs at the end, when its /workdir is most full.

And because tmpfs, being in memory, contributes to its container memory limit, it has much less memory to work with in this second make.bash later.

I thought there would be more information about the failure than just "exit status 2".

This test appears to be rebuilding the toolchain using the toolchain it just built as its bootstrap compiler. Doesn't that mean it will be changing/updating components of the toolchain as it is using those components for the new build?

go build cmd/compile/internal/ssa: /workdir/tmp/reboot-goroot202913779/pkg/tool/linux_ppc64le/compile: exit status 1
go tool dist: FAILED: /workdir/tmp/reboot-goroot202913779/pkg/tool/linux_ppc64le/go_bootstrap install -gcflags=all= -ldflags=all= -a -i cmd/asm cmd/cgo cmd/compile cmd/link: exit status 1
--- FAIL: TestRepeatBootstrap (100.86s)
    reboot_test.go:50: exit status 2

Here it is using /workdir/tmp/reboot-goroot202913779/pkg/tool/linux_ppc64le/compile to compile with but the result is an install of cmd/compile.

Change https://golang.org/cl/366538 mentions this issue: misc/reboot: skip TestRepeatBootstrap on short builders