pkg/vcs: use clang-15 for builds up to v6.15

Otherwise we need to backport too many fix commits to address build/boot
errors.

2 files changed, 11 insertions, 3 deletions

diff --git a/pkg/vcs/linux.go b/pkg/vcs/linux.go
index c0b96aaa4..e34fe9186 100644
--- a/pkg/vcs/linux.go
+++ b/pkg/vcs/linux.go
@@ -160,10 +160,12 @@ func (ctx *linux) EnvForCommit(
 
 func linuxClangPath(tags map[string]bool, binDir, defaultCompiler string) string {
 	version := ""
+	// The defaultCompiler and clang-15 are assumed to be available.
 	switch {
-	case tags["v5.9"]:
-		// Verified to work with 14.0.6.
+	case tags["v6.15"]:
 		return defaultCompiler
+	case tags["v5.9"]:
+		return "clang-15"
 	default:
 		// everything before v5.3 might not work great
 		// everything before v5.1 does not work
diff --git a/pkg/vcs/linux_test.go b/pkg/vcs/linux_test.go
index 5e81760a2..eb742c625 100644
--- a/pkg/vcs/linux_test.go
+++ b/pkg/vcs/linux_test.go
@@ -19,9 +19,15 @@ func TestClangVersion(t *testing.T) {
 	expected := binDir + "llvm-9.0.1/bin/clang"
 	assert.Equal(t, actual, expected, "unexpected clang path")
 
-	// Recent tag case.
+	// Older tag case.
 	tags["v5.9"] = true
 	actual = linuxClangPath(tags, binDir, defaultCompiler)
+	expected = "clang-15"
+	assert.Equal(t, actual, expected, "unexpected clang path")
+
+	// Recent tag case.
+	tags["v6.15"] = true
+	actual = linuxClangPath(tags, binDir, defaultCompiler)
 	expected = defaultCompiler
 	assert.Equal(t, actual, expected, "unexpected clang path")
 }