Matlab external diff missing sys/java/j​re/maca64/​jre/bin/ja​va on MATLAB R2023b

After upgrading to 2023b, the external comparison capability is no longer working on my m1 mac.

I have followed the steps here (Customize External Source Control to Use MATLAB for Diff and Merge - MATLAB & Simulink (mathworks.com))

1. Enabled MathWorks source control integration.
2. Run comparisons.ExternalSCMLink.setup() in the MATLAB command window.

When I attempt to run a comparison using the system terminal:

`git difftool --no-prompt -t mlDiff HEAD origin/master -- path/to/my/file.slx`

Here is the error message:

/Applications/MATLAB_R2023b.app/bin/maca64/diffLinkClient: line 23: /Applications/MATLAB_R2023b.app/sys/java/jre/maca64/jre/bin/java: No such file or directory
fatal: external diff died, stopping at path/to/my/file.slx

If I attempt to cd into `cd /Applications/MATLAB_R2023b.app/sys/java`, it appears that the directory java directory does not exist.

Is there a workaround for this?

[Walter Roberson]

I believe this is a limitation of R2023b on Mac Silicon

Answer 1

[John Goulet]

I found a workaround. You can symlink the java binary used by MATLAB (found by using jenv) to /Applications/MATLAB_R2023b.app/sys/java/jre/maca64/jre/bin/java

1. Get java bin location used by MATLAB

- In a matlab command window, enter `jenv`

- Copy the path of the java binary located in the 'Home' JavaEnvironment listed by `jenv`

2. Navigate to `/Applications/MATLAB_R2023b.app/sys/`

1. Create the subdirectory: `/java/jre/maca64/jre/bin/`

2. `cd /Applications/MATLAB_R2023b.app/sys/java/jre/maca64/jre/bin/`

3. `ln -s /Library/Java/JavaVirtualMachines/amazon-corretto-8.jdk/Contents/Home/jre/bin/java ./`

3. External diff should work