go/types: TestFixedbugs/issue70549.go fails on linux-s390x-ibm builder

[dmitshur]

The TestFixedbugs/issue70549.go test recently added in CL 662775 (for #70549) is consistently failing on linux-s390x-ibm and linux-s390x-ibm-race builders:

--- FAIL: TestFixedbugs (0.61s)
    --- FAIL: TestFixedbugs/issue70549.go (0.00s)
        check_test.go:281: ../../internal/types/testdata/fixedbugs/issue70549.go:12:11: no error expected: "undefined: math.sin (but have Sin)"
        check_test.go:319: --- p: unreported errors:
        check_test.go:323: ../../internal/types/testdata/fixedbugs/issue70549.go:12:11:  ERROR "name sin not exported by package math" 
        check_test.go:281: ../../internal/types/testdata/fixedbugs/issue70549.go:12:11: no error expected: "undefined: math.sin (but have Sin)"
        check_test.go:319: --- p: unreported errors:
        check_test.go:323: ../../internal/types/testdata/fixedbugs/issue70549.go:12:11:  ERROR "name sin not exported by package math" 
FAIL
FAIL	go/types	8.428s

(build log) (This wasn't caught by watchflakes because this builder hasn't been migrated to LUCI yet; that work is tracked in #67307.)

CC @golang/s390x, @mrkfrmn, @griesemer.

[gabyhelp]

Related Issues

• x/tools/go/packages: TestLoadImportsGraph is failing on s390x #29660 (closed)
• s390x broken by https://go-review.googlesource.com/c/go/+/173437 #31734 (closed)

Related Code Changes

• math: enable huge argument tests on s390x

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

[mrkfrmn]

The error seems to indicate that the private function sin plainly does not exist on s390x, not that it's just unexported.

Looking at the math library, it does appear that there is some special handling for s390x (see sin_s390x.s and friends).

[mrkfrmn]

Perhaps this is a sign that we should not be altering error behavior based on unexported package internals.

Though, it does appear that we could simply move to a different function like Sqrt and friends.

[gopherbot]

Change https://go.dev/cl/663635 mentions this issue: go/types, types2: fix failing error message test for s390x