SourceTree - external diff tool doesn't launch and conflicts disappear

[Gilly Dekel]

Hi

I am using SourceTree with Xcode's FileMerge. This has always worked fine. Today, when I right click->resolve using external diff tool, I get a window for a second showing that the launch is happening, and then nothing and the conflict disappears as though resolved. This is really bad as I am unable to merge changes.

Going into preferences, I tried to change the diff tool, but I can't click on any of the values - everything seems to be locked.

Help?

[easymile_vramiro]

I had the same problem, it turns out it was an Xcode problem

Run: sudo xcode-select -s /Applications/Xcode.app/Contents/Developer

[Andrea Ciani]

This worked for me

[Yogesh Randhawa]

This worked for me

[Alexey Shklyaev]

Yes that worked for me, using FileMerge

[danielmarcotte]

I have no idea what this command is doing, but it fixed my problem. Thank you.

[Roelof Koelewijn]

Super! this works for me.

[Riley Hooper]

Worked for me running SourceTree 2.7.6 (177) and Xcode 9.4.1.

[toni]

Thanks, solved by run that magic command.

[Rodrigo S_ Chavarria Rivera]

It works great for me, perfectly

[Becca Owens]

Worked for me. Thank you!

[Gabriele Trabucco]

I came from a clean Mac Installation ... As you said I found the command line tool was not properly configured. Nice catch! Thanks

[RichAppz]

Worked for me! Thanks

[kakitayuri]

Just a note for anyone else stumbling on this page - this appears to be a Mac thing, not an iOS thing. I'm an Android dev that doesn't much use Xcode, but this was exactly what I needed. Not the first time Xcode has screwed my dev environments.

[Rick Thomson]

I can confirm this worked for me, though had to change path to match my beta xcode location

[thefrosty]

Worked for me, since I've got a clean Mac installation.

[Jason Dahn]

Perfect, worked for me. Thank you!

[Joseph Razon]

Worked for me, tnx :)

[Tom Brückner]

Same here. Thanks.

[tigerzhang]

Worked for me, Thank you!

[halcyonix]

Also worked for me. Thanks a bunch!!

[Balázs Szakmáry]

• When the diff tool is not (correctly) configured, it behaves the way you described. (not very informative...)
• In Tools\Options\General, you need to enable "Allow SourceTree to modify your global config files" at the top before you can change the Diff settings.
• If you have the Diff / Merge tools set to "System default" (this is the default setting), it seems to never work.

So I think what you need to do is:

1. enable the "Allow..." option
2. change the diff tool to explicitly specify the right tool with the right cmd options

[Duarte Molha]

This is still not working for me. THe external diff tool does not launch!

[Trung Duy Van]

Thanks. It work perfect

[hussien_khayoon]

In Mac, I had to go to SourceTree/Preferences/General

[Lynna Landstreet]

This did not work for me. That option is checked, Diff/Merge tool is set explicitly to FileMerge (which is what it was using before it abruptly stopped working), and as recommended in another answer here, I have it set to Embedded Git rather than System Git, but none of that helped at all.

It used to work fine, and then suddenly stopped working a while back, without my having changed any configuration options whatsoever. I'm guessing it was when SourceTree automatically updated itself or something... But anyway, none of the answers in this post have helped for me.

[Jeff McKnight]

Tested with Sourcetree v2.7.1 and DiffMerge v4.2.1 (with command line tools) on MacOS v10.13.3:

1. Open Sourcetree prefs and select `Diff` tab

2. Set `Visual Diff Tool` menu to `Custom`

3. Set `Diff command` field to: /usr/local/bin/diffmerge

4. Set `Arguments` field to: $LOCAL $REMOTE

5. Close prefs, select External Diff (or cmd-D) and observe DiffMerg launches.

More info here:

https://sourcegear.com/diffmerge/webhelp/sec__git__mac.html

[t_anjan]

You can do the same for "Merge Command" too.

Merge Command:

/usr/local/bin/diffmerge

Arguments:

--merge --result="$MERGED" "$LOCAL" "$BASE" "$REMOTE"

[Jeff McKnight]

Works!

[jeremy_stafford]

None of these worked for me either. Using latest SourceTree with Beyond compare. It doesn't happen on every file. I don't know what the common factor is on the files that it does happen with. 

EDIT:

So it turns out the two files I was just trying to merge, the difference was that the file was no longer existent on the remote server. Rather than do something about the merge to show it was deleted, it just hung forever.

[jorge granados]

This was the right answer. Files no longer exist on remote server. 

[crobicha]

Was the solution for me as well. Can't believe there wasn't a simple error message or something, I spent a lot of time trying all of the other solutions, changing settings, etc

[Matt Brand]

This was what was happening for me. No diff = nothing happens.

[Joshua Wojcik]

I found changing to the Embedded Git rather than System Git fixed the problem.

[sean bzd]

this resolved my issue as well

[altaf-CosiGames]

this resolved my issue as well. I had tried with DiffMerge & Beyond Compare. Switching to System Git fixed it for me

[Thomas Luong]

This resolved my Issue.

[Jeff Sorrentino]

As a workaround I changed the name of my external diff app from

/Applications/DiffMerge

to

/Applications/_DiffMerge

Thus my diff command becomes

/Applications/_DiffMerge.app/Contents/MacOS/DiffMerge

with arguments

"$LOCAL" "$REMOTE" 

[Jonathan Oliver]

Even when I edited the .gitconfig diff tool path and fixed it by removing portion of the path, each time I'd restart DiffMerge, it would reappear.

/Applications/DiffMerge.app/Contents/MacOS/DiffMerge/Contents/MacOS/DiffMerge

So, here's the workaround.

1. Symlink DiffMerge to another location (so it's not auto-detected as DiffMerge)

ln -s /Application/DiffMerge.app /Applications/_DiffMerge.app

2. Then select a custom diff and merge tool arguments.

Diff command arguments:

--nosplash "$LOCAL" "$REMOTE"

Merge tool arguments:

--merge --result="$MERGED" "$LOCAL" "$BASE" "$REMOTE"

After this, SourceTree will no longer mangle the path at startup because it doesn't think it's DiffMerge anymore.

[voidpointer2]

Works for me.  

Just wanted to note:

ln -s /Application/DiffMerge.app /Applications/_DiffMerge.app

Should be:

ln -s /Applications/DiffMerge.app /Applications/_DiffMerge.app

 I can't believe this trivial bug has not been fixed yet.

[milennium9]

I had same problem.

1. open your git global config file.
2. check syntax error.

then I can fix the problem.

I think this is sourcetree bug.

[KevinCondon]

Yup, the path to diffmerge had part of it duplicated. Fixing it did the trick. Thanks!

[seanchon]

Same problem here. I had to accept the user agreement in the terminal before it would launch from SourceTree. Running 'sudo opendiff' worked for me.

[Val Gorbatyuk]

 This was it for me

[Patrick Galbraith]

I had this issue on Windows. The problem was caused by an upgrade that inserted backslashes "\" into the merge command arguments.

\"$LOCAL\" \"$REMOTE\"

Should be changed to:

"$LOCAL" "$REMOTE"

[ewbachtal]

Ooooooh!  A winner!  It's been months since external diff worked, I'd been through all the suggestions, saw those slashes but figured it was some sort of necessary string escaping and never considered that might be the cause.  Thank you!

[Becca Owens]

I was experiencing this as well, and discovered I'd had a derp moment. The file I was trying to merge had been deleted, therefore there was nothing to merge. :\

[Femi Ojemuyiwa]

Nothing above works anymore for diffmerge. Is there going to be a fix in next release or shall we just try any and every solution?

[Jonathan Oliver]

I just posted a reply above that works as off SourceTree v3.0

[GarethJ]

The fix is yet to arrove but there's a workaround at https://jira.atlassian.com/browse/SRCTREE-2211

[Brad Curran]

If none of these things work, try running `opendiff` in the Terminal. 

It there's an error like below you need to do one of two things: 

• Install XCode
• Install another diff program

As of writing SourceTree supports the following programs:

• Araxis Merge
• Beyond Compare
• BBEdit
• DiffFork
• DiffMerge
• Changes
• FileMerge
• Kaleidoscope
• KDiff3
• P4Merge
• TextWrangler

[greenboim]

Hi Yair,

I had the same problem.

As Balazs said, it was because the "System default" was selected for the merge tool. Download a tool and set it as your resolving tool.