[release-branch.go1.13] cmd/link: ensure cgo cflags do not leak into tvOS test

Running the 'TestBuildForTvOS' test with CGO_CFLAGS set
with certain values would cause the test to fail. all.bash
would fail when CGO_CFLAGS was set to '-mmacosx-version-min=10.10'
because the --macosx-version-min flag is incompatible with tvOS.
The change guards against using an unintended flag in the unit test.

Updates #36846
Updated #35459

Change-Id: Ifc43f3ebfb23d37aabeaac2ea9efae5b877991bf
Reviewed-on: https://go-review.googlesource.com/c/go/+/215957
Run-TryBot: Carlos Amedee <carlos@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
(cherry picked from commit ace25f82df0a27eb26a518e1883eb56c1bec6c5e)
Reviewed-on: https://go-review.googlesource.com/c/go/+/218598

diff --git a/src/cmd/link/link_test.go b/src/cmd/link/link_test.go
index 155fd8bce3b305afb8b7193338bfee99f2ac39fc..92bfcfd752d0989a818b0986669f063c0e9592ca 100644 (file)
--- a/src/cmd/link/link_test.go
+++ b/src/cmd/link/link_test.go
@@ -214,6 +214,7 @@ func TestBuildForTvOS(t *testing.T) {
                "GOOS=darwin",
                "GOARCH=arm64",
                "CC="+strings.Join(CC, " "),
+               "CGO_CFLAGS=", // ensure CGO_CFLAGS does not contain any flags. Issue #35459
        )
        if out, err := cmd.CombinedOutput(); err != nil {
                t.Fatalf("%v: %v:\n%s", cmd.Args, err, out)