mosml: dontPatchElf = true

This is because MosML needs the bin/camlrunm binary to have a
carefully calibrated RPATH pointing at its installation directory, and
patchelf will remove this.

Without this fix, MosML cannot dynamically load its own libraries
(most notably the "Unix" module).

pkgs/development/compilers/mosml/default.nix

@@ -15,6 +15,10 @@ stdenv.mkDerivation rec {
 
   setSourceRoot = ''export sourceRoot="$(echo */src)"'';
 
+  # MosML needs a specific RPATH entry pointing to $(out)/lib (added
+  # by the build system), which patchelf will remove.
+  dontPatchELF = true;
+
   meta = with lib; {
     description = "A light-weight implementation of Standard ML";
     longDescription = ''