How to resolve "abandoned transaction" when I use "hg push"?

If you are using bitbucket.com cloud solution and you get this error you need to open a ticket so they will run hg recover on their server.

They are very fast at answering tickets of this variety.

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.

You can login to sourceforge by ssh (https://sourceforge.net/p/forge/documentation/Shell%20Service/). Go into your hg folder, e.g. /home/hg/p/YOURPROJECTNAME/code, run hg recover here. Then everything's OK.