How to use Meld as git mergetool & difftool on WSL2?

Question

From WSL2 (Ubuntu) how could one use Meld installed natively on Windows as the git merge and diff tool? So that commands like git mergetool & git difftool from WSL open Meld on Windows.

Answer 1

Make meld easily accessible in WSL by linking it:

sudo ln -s /mnt/c/Program\ Files\ \(x86\)/Meld/Meld.exe /usr/local/bin/meld

In WSL edit ~/.gitconfig and add:

[diff]
        tool = meld
[difftool "meld"]
        cmd = meld \"$(wslpath -aw $LOCAL)\" \"$(wslpath -aw $REMOTE)\"
[merge]
        tool = meld
[mergetool "meld"]
        cmd = meld --auto-merge \"$(wslpath -aw $LOCAL)\" \"$(wslpath -aw $BASE)\" \"$(wslpath -aw $REMOTE)\" --output \"$(wslpath -aw $MERGED)\" --label=Local --label=Base --label=Remote --diff \"$(wslpath -aw $BASE)\" \"$(wslpath -aw $LOCAL)\" --diff \"$(wslpath -aw $BASE)\" \"$(wslpath -aw $REMOTE)\"

To make git difftool --dir-diff work you need to use it with --no-symlinks (the symbolic links in \\wsl$\ don't seem to currently work when opening from Windows apps). Changes will still be copied back to the source files once Meld is closed. Since I use git dir diff tool a lot I've added these aliases in the above file:

[alias]
        dt = !git difftool --dir-diff --no-symlinks -t meld
        mt = !git mergetool -t meld