Error log of launcher items

Question

I created a launcher item by hand:

How can I edit/create new launcher items in Unity by hand?

Years ago output like this was in .xsession-errors but modern ubuntu seems to use a different file.

If this fails starting. Where can I see the output?

Answer 1

I found the output of my failing launcher entry here:

.cache/upstart/gnome-session-Unity.log