I tried to file a bug at bugzilla.gnome.org, but I'm getting a 500 error when submitting, so posting here instead.
When trying to Alt-Del a change, I get the following exception:
Traceback (most recent call last):
File "/home/ahal/git/meld/meld/filediff.py", line 53, in wrap_function
return function(args[0], pane, *args[1:], **kwargs)
TypeError: delete_change() takes 2 positional arguments but 3 were given
I've hacked around the problem locally (though not good enough to submit a patch). So this is an FYI, not a request for help.