Merge pull request #508 from input-output-hk/fix-nix-build

fix(nix): fix not found /packages/cardano-services/node_modules

Author: rhyslbw

flake.nix

@@ -76,7 +76,7 @@
             cp -r packages/$p/dist $out/libexec/$sourceRoot/packages/$p/dist
             cp -r packages/$p/package.json $out/libexec/$sourceRoot/packages/$p/package.json
           done
-          cp -r ${production-deps}/libexec/$sourceRoot/packages/cardano-services/node_modules $out/libexec/$sourceRoot/packages/cardano-services/node_modules
+          test -f ${production-deps}/libexec/$sourceRoot/packages/cardano-services/node_modules && cp -r ${production-deps}/libexec/$sourceRoot/packages/cardano-services/node_modules $out/libexec/$sourceRoot/packages/cardano-services/node_modules
           cp -r ${production-deps}/libexec/$sourceRoot/packages/cardano-services/config $out/libexec/$sourceRoot/packages/cardano-services/config
 
           cd "$out/libexec/$sourceRoot"