Trying to push some new code to a Hg repository on my Dreamhost account, I had the following error message :
remote: *** failed to import extension hgext.imerge: No module named imerge
I used to have the same kind of issues with an other extensions, hgext/hbisect a while ago and I fixed it by forcing Hg to not use this extension.
Here's how :
Edit your .hgrc file and under the [extensions] category, add hgext.imerge=!, like this
[extensions]
hgext/hbisect = !
hgext.imerge=!
This should stop the warning.