I try to tweak the mathoid code and find the error message unreadable, the stack trace is displayed as a string with '\n' as linebreaks.
This is the setup:
```
git clone ssh://golopotw@gerrit.wikimedia.org:29418/mediawiki/services/mathoid
npm install
node server.js
curl -d localhost:10044
```
The error look like this
```
"message":"500: internal_error","stack":"ReferenceError: app is not defined\n at /home/jchn/mathoidq/routes/info.js:15:15\n at Layer.handle [as handle_request] (/home/jchn/mathoidq/node_modules/express/lib/router/layer.js:95:5)\n at next (/home/jchn/mathoidq/node_modules/express/lib/router/route.js:137:13)\n at Route.dispatch (/home/jchn/mathoidq/node_modules/express/lib/router/route.js:112:3)\n at Layer.handle [as handle_request] (/home/jchn/mathoidq/no
```