I'm using Git with VS2017 Enterprise, and if I right-click a file in Changes and choose "Compare with unmodified" it opens in a new window in VS using the VS diff tool.
I would like to use WinMerge instead, and have been looking at resources such as this (instructions for BeyondCompare, but the principle should be the same), this (ditto for GitExtensions) and this, but cannot get it to work. Whatever I do, I still get the VS diff tool in VS.
The .gitconfig file in my user folder looks like this...
[user]
name = Me
email = myemail@somewhere.jim
[core]
autocrlf = true
[diff]
tool = winmerge
[difftool "winmerge"]
cmd = "'C:/Program Files (x86)/WinMerge/WinMergeU.exe'" -e "$LOCAL" "$REMOTE"
...and the .git/config file in my project folder looks like this (sensitive info changed)...
[core]
repositoryformatversion = 0
filemode = false
bare = false
logallrefupdates = true
symlinks = false
ignorecase = true
[user]
[diff]
tool = winmerge
[difftool]
prompt = true
[difftool "winmerge"]
cmd = "/c/Program\\ Files\\ \\(x86\\)/WinMerge/WinMergeU.exe" -u -e $LOCAL $REMOTE
keepBackup = false
[merge]
tool = vsdiffmerge
[mergetool]
prompt = true
[remote "origin"]
url = https://me@dev.azure.com/me/Project/_git/Project
fetch = +refs/heads/*:refs/remotes/origin/*
[branch "master"]
remote = origin
merge = refs/heads/master
[gui]
wmstate = normal
geometry = 1346x938+75+75 445 196
Anyone able to tell me what I need to do to use WinMerge?
Your problem is that...
/c/Program\\ Files\\ \\(x86\\)/WinMerge/WinMergeU.exe
...is an incorrect path. If you look in your first code snippet, you'll see the correct path, however this is overridden by the project's config file.
If you change the path in the second snippet, or (better still) remove that whole section, as it only duplicates what's in the first, then you should find it will work.