Settings for Linux and OS X

First confirm that /usr/bin/diffmerge or /usr/local/bin/diffmerge is present. If you used the PKG Installer on OS X this was also installed when /Applications/DiffMerge.app was installed. If you used the DMG file, refer to the instructions for installing the Extras. On Linux, this should have been installed for you.

Add the following lines to your .hgrc:

[extensions]
hgext.extdiff =

[extdiff]
cmd.diffmerge = /usr/bin/diffmerge

[merge-tools]
diffmerge.executable = /usr/bin/diffmerge
diffmerge.args = --result=$output  $local $base $other
diffmerge.binary = False
diffmerge.symlinks = False
diffmerge.gui = True
diffmerge.premerge = True