cmd/compile/internal/ssa: TestNexting/dlv-dbg-hist failing on linux-386-longtest builder because it tries to use an older version of dlv which only supports linux/amd64

[dmitshur]

(Factoring out this specific problem from #37050.)

The TestNexting/dlv-dbg-hist test is failing on linux-386-longtest builder on release-branch.go1.14 and release-branch.go1.13:

• https://build.golang.org/?branch=release-branch.go1.14

  

• https://build.golang.org/?branch=release-branch.go1.13

  

See #37050 (comment) and other comments for more details.

This is determined to be a problem of the test, because delve doesn't support linux/386 (according to #37050 (comment)), yet it's attempted to be used by the test.

To make progress, we need to decide how best to improve this test so it no longer fails.

(Note the test is flaky on linux/amd64 for unrelated reasons, and skipped on tip; that is tracked in issue #37404.)

/cc @dr2chase @cagedmantis @toothrot @andybons

[dmitshur]

This is determined to be a problem of the test, because delve doesn't support linux/386 (according to #37050 (comment)), yet it's attempted to be used by the test.

I was looking up a reference for that, and learned that support for linux/386 was added to delve as recently as a few months ago in Delve 1.4.1 (see CHANGELOG and go-delve/delve#1884). The version of Delve currently available in the linux-386-longtest builder is 1.2.0.

This test is completely skipped on 1.15 branch because it's flaky (see #37404, /cc @bcmills). As a result, it doesn't seem worth investing a lot in trying to fix this test on 386 in its current state.

For now, I'll write a comment saying that the version of delve installed on linux-386-longtest doesn't yet support linux/386 and skip for that reason. It seems reasonable to me that if we want to add support for TestNexting using delve on linux/386, we can consider doing that in a future version of Go (e.g., 1.15 or later).

[gopherbot]

Change https://golang.org/cl/237603 mentions this issue: cmd/compile/internal/ssa: skip TestNexting with old delve on linux/386

[dmitshur]

@gopherbot Please consider for backport, this is a test skip for a test that is expected not to pass due to insufficient environment preconditions. This is to uncover additional test failures on the linux-386-longtest builder that would otherwise be masked.

[gopherbot]

Backport issue(s) opened: #39561 (for 1.13), #39562 (for 1.14).

Remember to create the cherry-pick CL(s) as soon as the patch is submitted to master, according to https://golang.org/wiki/MinorReleases.