I'm working with a lot of anonymous functions, ie functions declared as part of a dictionary, aka "methods". It's getting pretty painful to debug, because I can't tell what function the errors are happening in.

Vim's backtraces look like this:

Error detected while processing function NamedFunction..2111..2105:
line    1:
E730: using List as a String

This trace shows that the error occurred in the third level down the stack, on the first line of anonymous function #2105. IE NamedFunction called anonymous function #2111, which called anonymous function #2105. NamedFunction is one declared through the normal function NamedFunction() ... endfunction syntax; the others were declared using code like function dict.func() ... endfunction.

So obviously I'd like to find out which function has number 2105.

Assuming that it's still in scope, it's possible to find out what Dictionary entry references it by dumping all of the dictionary variables that might contain that reference. This is sort of awkward and it's difficult to be systematic about it, though I guess I could code up a function to search through all of the loaded dictionaries for a reference to that function, watching out for circular references. Although to be really thorough, it would have to search not only script-local and global dictionaries, but buffer-local dictionaries as well; is there a way to access another buffer's local variables?

Anyway I'm wondering if it's possible to dump the source code for the anonymous function instead. This would be a lot easier and probably more reliable.