llvm: support cross compilation with useLLVM flag

You can build (partially) with LLVM toolchain using the useLLVM flag.
This works like so:

  nix-build -A hello --arg crossSystem '{ system =
    "aarch64-unknown-linux-musl"; useLLVM = true }'

also don’t separate debug info in lldClang

It doesn’t work currently with that setup hook. Missing build-id?

1 files changed, 1 insertions, 1 deletions

diff --git a/pkgs/stdenv/generic/make-derivation.nix b/pkgs/stdenv/generic/make-derivation.nix
index cafd1031ab8b..39b84179ae07 100644
--- a/pkgs/stdenv/generic/make-derivation.nix
+++ b/pkgs/stdenv/generic/make-derivation.nix
@@ -86,7 +86,7 @@ rec {
       doCheck' = doCheck && stdenv.hostPlatform == stdenv.buildPlatform;
       doInstallCheck' = doInstallCheck && stdenv.hostPlatform == stdenv.buildPlatform;
 
-      separateDebugInfo' = separateDebugInfo && stdenv.hostPlatform.isLinux;
+      separateDebugInfo' = separateDebugInfo && stdenv.hostPlatform.isLinux && !(stdenv.hostPlatform.useLLVM or false);
       outputs' = outputs ++ lib.optional separateDebugInfo' "debug";
 
       fixedOutputDrv = attrs ? outputHash;