How to solve a Mercurial case-folding collision?

I use Mercurial as source control with the main repository managed on KILN. At one point in time I changed my iOS project name from WeatherTimeMachine to weathertimemachine. This resulted in a case change of several files and folders:

• WeatherTimeMachine.xcode
• WeatherTimeMachine_Prefix.pch
• WeatherTimeMachine-Info.plist

In the meantime I've added a tag to a revision in KILN... So I now have:

• a head in KILN
• a head on my local repo with case changes

When trying to merge I get the following error message: "Mercurial case-folding collision"

How can I fix this?

I have found some information here: FixingCaseCollisions, but somehow this did not work for me. Here is how I managed to solve this issue:

Make a copy of your existing repository folder (for safety). For example:

• cp -r WeatherTimeMachine WeatherTimeMachineCopy

Fool mercurial into thinking the problematic revision is the current tip:

• hg debugsetparents <bad revision>
• hg debugrebuildstate

Remove the files which are causing the problem (-f is required to force the removal). Here is an example:

• hg rm -A -f WeatherTimeMachine-Info.plist

Once all problematic files have been removed, commit the changes

• hg ci -m "fixed collision-folding issue" -u michael

Then restore mercurial to the proper revision

• hg debugsetparents tip
• hg debugrebuildstate

After this the merge is possible and the problem is gone.

And now I can happily resume working with MacHg to manage my Mercurial repository and push my change sets to KILN.