Q: TypeError at formatLambdaLocalError when fetching using Netlify Functions and netlify dev When calling a netlify function during local netlify dev testing, the netlify dev servers kept crashing with the following error:
TypeError: Cannot read properties of undefined (reading 'join') at formatLambdaLocalError ... at at processRenderedResponse ... at handleErr ... at handleSynchronousFunction ... etc

In the end I found that I accidentally changed the return flow-statement to a throw flow-statement within the catch-block of my try..catch structure. Independent of the type of error encountered in the try-statement, the same error shown above is printed when the server crashes due to this throw flow-statement.
I hope by sharing this already-solved problem here, I can save you a few days of debugging!
