I was able to connect to the remote container until recently. I think I made some changes on my local directory, but I'm not sure what is causing the problem.
When connecting to the remote container, we will copy the local version of your code to the remote container and then build your project. If cmake is not able to build your project because the code contains syntax errors, you will need to correct the errors before trying again.
It could take quite some time to build the image and find out that you have a syntax error in your code that does not allow you to connect to the remote container. In order to avoid this pain, we suggest you switch to a branch or version of the code that is exempt of syntax errors. That way you will be able to connect into the remote container without problem. Once inside the remote container, you can then make the changes you want and try to test the correctness of your code syntax by running the code with ROS: Launch.