(when adding jar) - Module “android” must not contain source root

Question

I\'m trying to add gdx-tools.jar to a libGDX project in IntelliJ. The result:

Module \"android\" must not contain source root \".../android/src\". The

Answer 1

simple 'delete my_project.iml file and import project once again using File->New->Project From Existing Sources'

Answer 2

I had run into a similar issue as well:

Module "(my_project)" must not contain source root "(my project)/src". The root already belongs to module "(my_project)".

As I couldn't do anything on IDEA's configuration UI, I opened up the IDEA project file (my_project.iml) in vi, hoping to find out what's wrong:

<sourceFolder url="file://$MODULE_DIR$/my_project/src" type="java-resource" />
<sourceFolder url="file://$MODULE_DIR$/my_project/src" isTestSource="false" />
<!-- Duplicate entry found in project file -->

So eventually I solved my case by removing the duplicate entry manually.

As the IDEA project files were generated automatically from Gradle files, I have no idea what caused the duplicate entries to be created, but for those facing similar issues, a quick glance at the .iml file may help.