We work with a sourceforge project. When we try to push, then mercurial abort :
$ hg push
pushing to ssh://<user>@hg.code.sf.net/p/loremipsum/code
searching for changes
remote: abort: abandoned transaction found - run hg recover!
abort: unexpected response: empty string
And when we try to recover that doesn't work :
$ hg recover
no interrupted transaction available
The other programmers of the project have the same problem. We are a lost.
In my case I had to run
hg recover
on the remote machine to which I was pushing to. It fixed the problems and I could push the changes from my machine.