Fix for ghcjs

Author: hamishmack

builder/comp-builder.nix

@@ -514,7 +514,7 @@ let
         if [ -f ${testExecutable} ]; then
           mkdir -p $(dirname $out/bin/${exeName})
           ${if stdenv.hostPlatform.isGhcjs then ''
-            cat <(echo \#!${lib.getBin buildPackages.nodejs-12_x}/bin/node) ${testExecutable} >| $out/bin/${exeName}
+            cat <(echo \#!${lib.getBin buildPackages.nodejs-18_x}/bin/node) ${testExecutable} >| $out/bin/${exeName}
             chmod +x $out/bin/${exeName}
           '' else ''
              cp -r ${testExecutable} $(dirname $out/bin/${exeName})