x/build/cmd/buildlet: $PATH miscomputed when set in "env" parameter, causing test failures on aix-ppc64

[Helflym]

The tests of x/tools and x/tour are failing on aix/ppc64, because the builder seems to use an hybrid version between 1.12.1 and master. Any idea of what must be changed/fixed ?

https://build.golang.org/log/b7b160e7a7e733fbe768d45af70cf1c626ac4289
https://build.golang.org/log/7e28abbbd860c0ea1f212805b15ce5f3e8bf5d14

/cc @bradfitz

Edit by @dmitshur: The root cause of this problem is described in #31567 (comment).

[bradfitz]

I don't know what's going on there.

Per the first line of that first URL, it should only be using Go built at c8aaec2, which you see later in the log with:

# internal/cpu
compile: version "devel c8aaec2f70c5ccbca1ec2152c57d19981ac09133" does not match go tool version "go1.12.1"

So I don't know why it's expecting Go 1.12.1 or where that comes from.

/cc @ianlancetaylor @bcmills @dmitshur

[bcmills]

There are two PATH entries in the command line logged at the top:

"PATH=/ramdisk8GB/workdir-host-aix-ppc64-osuosl/go/bin:/opt/freeware/bin:/usr/bin:/etc:/usr/sbin:/usr/ucb:/usr/bin/X11:/sbin:/usr/java7_64/jre/bin:/usr/java7_64/bin"

and

"PATH=/opt/freeware/bin:/usr/bin:/etc:/usr/sbin:/usr/ucb:/usr/bin/X11:/sbin:/usr/java7_64/jre/bin:/usr/java7_64/bin"

The latter does not include $GOROOT/bin, so that's presumably where the go at 1.12.1 is coming from.

I don't know why compile is coming from the devel version, though.

[Helflym]

I think the second path comes from https://go-review.googlesource.com/c/build/+/152457. However, they are supposed to be merged together or at least $GOROOT/bin should be added to the $PATH coming from the dashboard.

[bradfitz]

I don't know why compile is coming from the devel version, though.

Because this is a build that's running repo "go" at master (rev c8aaec2f70c5ccbca1ec2152c57d19981ac09133) against x/net master.

[bradfitz]

But, yeah, double/unmerged PATH definitely looks like the problem here. Thanks for noticing that and for the CL link.

[gopherbot]

Change https://golang.org/cl/192327 mentions this issue: dashboard: disable failing repos on misconfigured builders

[gopherbot]

Change https://golang.org/cl/192335 mentions this issue: dashboard: extend aix-ppc64 skip to the website repo