I just spent a few minutes debugging an error from development storage. Thought I'd write it up here in case someone else hits it.
I created a new table, and a new entity to put in it. Every time I tried to insert the entity I'd get back a 500 Internal Server Error from development storage, with no more explanation.
It turns out that if one of the entity field names is the same as the table name, it causes a 500 error. eg, if I have a table called "MyData", and I try to insert an entity which has a field called "MyData", it fails every time. It seems to work fine in
real storage though.
It would be nice if they could fix some of these devstorage bugs. We develop and unit test against devstorage, so even though devstorage bugs are not production bugs I still have to debug them and write workarounds for them.