FileMerge quits immediately after launching from SourceTree
XcodeAtlassian SourcetreeFilemergeXcode Problem Overview
I regularly use Atlassian SourceTree (on Mac OS X) to launch FileMerge to resolve git merge conflicts. Out of the blue it has stopped working: when I right click and select Resolve Conflicts > Launch External Merge Tool
, FileMerge launches, creates its intermediate files, then immediately exits. SourceTree interprets that as the merge process being complete.
What's the issue and how can I debug/fix it?
I note that a previous question 'SourceTree filemerge quits immediately and creates 4 files. How to fix it?' does not address this particular scenario (for one, it says FileMerge quits in the title, but in the body it says FileMerge displays /dev/null as one of the panels. Additionally, my merge conflict is not due to a removed file.)
Xcode Solutions
Solution 1 - Xcode
To diagnose the problem, I ran opendiff
from the Terminal. I received the following error:
>xcode-select: error: tool 'opendiff' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance
To solve:
- Open Xcode > Preferences > Locations
- Click on the drop-down box beside Command Line Tools and select your current Xcode version. (This was empty for me because I had recently installed Xcode on a new Mac.)
- Run
opendiff
in Terminal again, and the above error should no longer appear.
Now FileMerge will open correctly from SourceTree when you click Launch External Merge Tool.
Solution 2 - Xcode
For me, SourceTree didn't even launch FileMerge. When clicking Launch External Merge Tool nothing happened.
Moreover, running opendiff
in Terminal worked as expected:
$ opendiff
opendiff[64176:5561154] too few arguments
opendiff[64176:5561154] usage: opendiff file1 file2 [-ancestor ancestorFile] [-merge mergeFile]
What helped me was manually configuring SourceTree to use FileMerge via the opendiff
command with the following arguments: $LOCAL $REMOTE -ancestor $BASE -merge $MERGED
This way, SourceTree opens FileMerge as expected.
Solution 3 - Xcode
This helped: https://gist.github.com/kylefox/4512777
Tell system when Xcode utilities live:
sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer
Set "opendiff" as the default mergetool globally:
git config --global merge.tool opendiff
Solution 4 - Xcode
If Xcode has recently updated itself, you may need to agree to the new license terms. If you have not agreed to the license terms, FileMerge (when launched from SourceTree) will quit immediately.
To check for this, open a shell and run as your usual user:
$ opendiff
If the license is the problem, it will tell you. To agree to the new license terms, you'll need to run open diff using sudo
:
$ sudo opendiff
After agreeing to the license terms, you can now retry launching FileMerge from SourceTree using Resolve Conflicts > Launch External Merge Tool
. FileMerge should launch and behave normally.
Solution 5 - Xcode
This also works to resolve the message "xcode-select: error: tool 'opendiff' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance":
sudo xcode-select -s /Applications/Xcode.app/Contents/Developer
Solution 6 - Xcode
I have encountered this problem and solved it with the answer here
So this time, when I had it again, I thought the same issue happened...
And after trying for almost an hour, I've realized that the Diffmerge (or any external diff tool) did not open because there was no file in the current branch to merge.
This can happen when you do Cherry Pick where the commits can be jumpy. Added this answer to remind people who are going to have the same issue.