git mergetool is wonderful (in my case, I use kdiff3). However, it is not possible to use it to resolve conflicts from git am or git apply (or even with patch command). Indeed, mergetool need 3 files to work (base and both modified versions) while git am work with a modified version and a patch.
Do you know a way to use git mergetool for conflicts produced with git am?
I think it is necessary to guess the base file from modified version and patch. If you consider each chunk separately, it looks tricky, but not impossible.
 
                        
As torek mentions,
git mergetoolwill be involved if you are:git am --3wayam.threeWayset to true.The issue remains for a regular patch command.