Today my git mergetool stopped working. When I ran
git mergetool I was greeted with:
git config option merge.tool set to unknown tool: --global Resetting to default... This message is displayed because 'merge.tool' is not configured. See 'git mergetool --tool-help' or 'git help config' for more details. 'git mergetool' will now attempt to use one of the following tools: tortoisemerge emerge vimdiff No known merge tool is available.
Somehow (seriously, I have no idea how I did this) I had created a setting in one of my repositories set my mergetool to
If you happen to get yourself into the same issue, run
git config --list to see what your config settings are.
For me, I had a rogue
merge.tool entry, so I just had to run
git config --unset merge.tool which deleted the entry and I was off again.