internal/rosa: provide package metadata

This had to be done out-of-band because there was no way to efficiently represent these within Artifact.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/llvm.go

@@ -216,6 +216,10 @@ func (t Toolchain) newLLVM() (musl, compilerRT, runtimes, clang pkg.Artifact) {
 		{"LLVM_ENABLE_LIBXML2", "OFF"},
 	}
 
+	muslHeaders, _ := t.newMusl(true, []string{
+		"CC=clang",
+	})
+
 	compilerRT = t.newLLVMVariant("compiler-rt", &llvmAttr{
 		env: stage0ExclConcat(t, []string{},
 			"LDFLAGS="+earlyLDFLAGS(false),
@@ -237,9 +241,9 @@ func (t Toolchain) newLLVM() (musl, compilerRT, runtimes, clang pkg.Artifact) {
 			{"COMPILER_RT_BUILD_XRAY", "OFF"},
 		},
 		append: []string{"compiler-rt"},
-		nonStage0: []pkg.Artifact{t.newMusl(true, []string{
-			"CC=clang",
-		})},
+		nonStage0: []pkg.Artifact{
+			muslHeaders,
+		},
 		script: `
 mkdir -p "/work/system/lib/clang/21/lib/"
 ln -s \
@@ -255,7 +259,7 @@ ln -s \
 `,
 	})
 
-	musl = t.newMusl(false, stage0ExclConcat(t, []string{
+	musl, _ = t.newMusl(false, stage0ExclConcat(t, []string{
 		"CC=clang",
 		"LIBCC=/system/lib/clang/21/lib/" +
 			triplet() + "/libclang_rt.builtins.a",