Step 1: Get the code into IntelliJ

Start IntelliJ.

IntelliJ shows the following window:

Click on “Open”

Choose build.gradle in the root of the jabref source folder:

Open File or Project dialog — Choose `build.gradle` in the “Open Project or File” dialog

After pressing “OK”, IntelliJ asks how that file should be opened. Answer: “Open as Project”

Choose “Open as Project” in the Open Project dialog

Then, trust the project:

Trust and Open Project dialog — Choose “Trust Project” in the “Trust and Open Project” dialog

Ensure that committing via IntelliJ works

IntelliJ offers committing using the UI. Press Alt+0 to open the commit dialog.

Unfortunately, IntelliJ has no support for ignored sub modules [IDEA-285237]. Fortunately, there is a workaround:

Go to File > Settings… > Version Control > Directory Mappings.
Note: In some MacBooks, Settings can be found at the “IntelliJ” button of the app menu instead of at “File”.

Currently, it looks as follows:

Directory Mappings including sub modules — Directory Mappings unmodified

You need to tell IntelliJ to ignore the submodules buildres\abbrv.jabref.org, src\main\resources\csl-locales, and src\main\resources\csl-styles. Select all three (holding the Ctrl key). Then press the red minus button on top.

This will make these directories “Unregistered roots:”, which is fine.

Directory Mappings having three repositories unregsitered — Directory Mappings having three unregistered roots