MEX file cannot be opened because the developer cannot be verified in OS X 10.15.2 and cannot be added to the authorization list.

I have a MEX file and when I open it in OSX 10.15.2 Catalina, the system throws a message saying "cannot be opened because the developer cannot be verified".

It can only be opened while I disable Gatekeeper entirely. It does not work when I add the MEX files as exception using 'spctl --add'. 

Is there any way I can add the file to the authorization list without disabling Gatekeeper entirely?

Answer 1

[MathWorks Support Team]

1. Check to see if the file is quarantined by running the following command in the terminal:

xattr /path/to/file

An entry “com.apple.quarantine” means the library has been quarantined

2. Remove this attribute by running the following command in the terminal:

sudo xattr -r -d com.apple.quarantine /path/to/file

3. Try to run the MEX file again

[Walter Roberson]

Note: quarantine changed in MacOS Ventura; see https://eclecticlight.co/2023/03/13/ventura-has-changed-app-quarantine-with-a-new-xattr/