Visual Studio Code – Error in Visual srudio code java extension: Set other project in source path: The source path must be contained in the project root folder

Suppose I have 4 independent Java projects: project0, project1, project2, and project3.

Inside each project, I have the src folder, and inside some packages and classes. Project 1, 2, and 3 use classes from project0.

In Eclipse, I can indicate in a section that the sources of project 0 are used.
When I try something similar in VScode, I go to configure the classpath of project one and see that it includes its src folder. When I add the src folder of project0, I get the following error: "The source path must be contained in the project root folder."

I can solve this by creating the .jar of project 0 and adding it to the other projects, but this is very inconvenient when making quick tests.

I know there are tools like Maven or Ant to do these things, but I would like to know if there is any way to indicate in vscode that one project uses classes from another without having to include the .jar as a dependency.

projeca0
-src
 -package0
   -class0

peoject1
 -src
 -package1
  -class1

If class1 uses class0, it will fail. I wish add project0/src as dependency of project1 without creatinfg project0 .jar and add it to project 1.