Fix musl copy

Author: angerman

compiler/ghc/default.nix

@@ -799,19 +799,17 @@ stdenv.mkDerivation (rec {
       then ''
         mkdir $out
         cp -r _build/stage1/bin $out
-        ${
-          # These are needed when building the reinstallable lib ghc
-          if targetPlatform.isMusl
-            then ''
-              cp _build/stageBoot/bin/genprimopcode $out/bin
-              cp _build/stageBoot/bin/deriveConstants $out/bin
-            '' else ''
-              cp _build/stageBoot/bin/${targetPrefix}genprimopcode $out/bin
-              ln -s $out/bin/${targetPrefix}genprimopcode $out/bin/genprimopcode
-              cp _build/stageBoot/bin/${targetPrefix}deriveConstants $out/bin
-              ln -s $out/bin/${targetPrefix}deriveConstants $out/bin/deriveConstants
-            ''
-        }
+        # let's assume that if we find a non-prefixed genprimop,
+        # we also find a non-prefixed deriveConstants
+        if [ -f _build/stage1/bin/genprimopcode ]; then
+          cp _build/stageBoot/bin/genprimopcode $out/bin
+          cp _build/stageBoot/bin/deriveConstants $out/bin
+        else
+          cp _build/stageBoot/bin/${targetPrefix}genprimopcode $out/bin
+          ln -s $out/bin/${targetPrefix}genprimopcode $out/bin/genprimopcode
+          cp _build/stageBoot/bin/${targetPrefix}deriveConstants $out/bin
+          ln -s $out/bin/${targetPrefix}deriveConstants $out/bin/deriveConstants
+        fi
         cp -r _build/stage1/lib $out
         mkdir $doc
         cp -r _build/stage1/share $doc