crypto/ed25519: test fixup

Fix up TestEd25519Vectors to download files into its own temporary mod
cache, as opposed relying on whatever GOPATH or GOMODCACHE setting is
in effect when the test is run.

Change-Id: I523f1862f5874b0635a6c0fa83d35a6cfac6073b
Reviewed-on: https://go-review.googlesource.com/c/go/+/402154
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/crypto/ed25519/ed25519vectors_test.go b/src/crypto/ed25519/ed25519vectors_test.go
index 74fcdcdf4e6612b8259f2f64ad62b20850d7e6d9..f933f2800a4b51c5407c20e22a6357470ff47b22 100644 (file)
--- a/src/crypto/ed25519/ed25519vectors_test.go
+++ b/src/crypto/ed25519/ed25519vectors_test.go
@@ -74,11 +74,22 @@ func TestEd25519Vectors(t *testing.T) {
 func downloadEd25519Vectors(t *testing.T) []byte {
        testenv.MustHaveExternalNetwork(t)
 
+       // Create a temp dir and modcache subdir.
+       d := t.TempDir()
+       // Create a spot for the modcache.
+       modcache := filepath.Join(d, "modcache")
+       if err := os.Mkdir(modcache, 0777); err != nil {
+               t.Fatal(err)
+       }
+
+       t.Setenv("GO111MODULE", "on")
+       t.Setenv("GOMODCACHE", modcache)
+
        // Download the JSON test file from the GOPROXY with `go mod download`,
        // pinning the version so test and module caching works as expected.
        goTool := testenv.GoToolPath(t)
        path := "filippo.io/mostly-harmless/ed25519vectors@v0.0.0-20210322192420-30a2d7243a94"
-       cmd := exec.Command(goTool, "mod", "download", "-json", path)
+       cmd := exec.Command(goTool, "mod", "download", "-modcacherw", "-json", path)
        // TODO: enable the sumdb once the TryBots proxy supports it.
        cmd.Env = append(os.Environ(), "GONOSUMDB=*")
        output, err := cmd.Output()