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External diff tool FileMerge don't start when I press the "Diff Externe" button.

External diff tool FileMerge don't start when I press the "Diff Externe" button. Other external diff tools works correctly such as DiffMerge, but I had to add a softlink.

For FileMerge tool, nothing is modifiable when we select it. Adding a softlink did not improve the situation:

sudo ln -sf /Developer/Applications/Utilities/ /usr/bin/FileMerge

This trick worked file for diffmerge but not for FileMerge.

Here are the details of the links I did:

lrwxr-xr-x 1 root wheel 59 12 fév 10:18 /usr/bin/diffmerge -> /Applications/
lrwxr-xr-x 1 root wheel 72 13 fév 19:51 /usr/bin/filemerge -> /Developer/Applications/Utilities/
lrwxr-xr-x 1 root wheel 72 13 fév 19:51 /usr/bin/FileMerge -> /Developer/Applications/Utilities/

Thanks for your help.

5 answers

1 accepted

6 votes
Answer accepted

Thanks for the tip about opendiff as the name.

I ran opendiff on a command line and got:

Mac-mini-de-Patrick:~ patrickjeanson$ opendiff
xcode-select: Error: No Xcode folder is set. Run xcode-select -switch <xcode_folder_path> to set the path to the Xcode folder.
Error: /usr/bin/xcode-select returned unexpected error.

So I did the following command on a terminal:

Mac-mini-de-Patrick:~ patrickjeanson$ sudo xcode-select -switch /Developer
Mac-mini-de-Patrick:~ patrickjeanson$ opendiff
2012-02-14 18:43:14.542 opendiff[31684:10f] too few arguments
2012-02-14 18:43:14.547 opendiff[31684:10f] usage: opendiff file1 file2 [-ancestor ancestorFile] [-merge mergeFile]


I set the right parameters in SourceTree and the diff was launched properly.

ie. opendiff $BASE $LOCAL

Thanks to all.


Thanks, I'll add this to the Knowledge Base too.

Quick tips : I just had to run `sudo opendiff` and then accept the license. After opendiff open properly.

SourceTree 1.9.8

XCode 6.0.1

Thank you, this worked great for me.

Worked for me as well. Thank you!

When I do `sudo opendiff` at the command line, I get:

xcode-select: error: tool 'opendiff' requires Xcode, but active developer directory '/Library/Developer/CommandLineTools' is a command line tools instance

You need to install Command Line Tools in Xcode Preferences -> Locations (as of Xcode 10.2.1)

I've been struggling with this as well — seems it's a problem with other apps, I followed the instructions here

It doesn't come pre-installed with Command Line tools, install them under Xcode preferences then:

sudo /usr/bin/xcode-select -switch /Applications/

That seems to do the trick!

SourceTree actually needs to use the command line tool for FileMerge, which is called 'opendiff'. This should have been installed when you installed XCode, it usually lives in /usr/bin/opendiff.

OK, I think they moved it to /Developer/usr/bin/opendiff. Probably the best way to resolve this is to add /Developer/usr/bin to your /etc/paths - or you could symlink opendiff to somewhere on one of your existing paths.

Hmm, actually I wonder whether this is installed if you've only ever installed XCode from the Mac App Store. If it's missing, that would explain things, but I wonder where it's gone in that case.

I also needed to run

sudo opendiff

as Xcode was complaining that I'd not agreed to the license. After this File Merge worked as expected.

Thank you.

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