Is there a way to stop evaluation, when it takes too long or is in an endless loop? I can kill the jvm task, but that seems a bit too much?

There is an Interrupt Running Evaluations command for that. Depending on the nature of the hang, it might not work, but most often it does, is my experience.

Thanks, I'll try this

Dear Calva friends. I apologise in advance for any inconvenience brought by the Calva version just released: v2.0.139. It has a workaround for an issue with lsp on Windows. But that is not what I think might cause inconveniences. That comes in with a change to Calva jack-in where we move away from abusing the VS Code Task system to a solution where we use the Pseudo Terminal APi to control the jack-in process. This has been very long in the works and I have never dared release it. But I am out of ideas on what might break now and it doesn’t seem people are very interested in testing the VSIX-es I’ve put out (probably because it is quite unclear what it is about). So, now, with hopes that it shouldn’t break things, but fears that it might, it is released. Please be quick to test that jack-in still works for you as it used to.

Since ^ v2.0.140 is out, with a fix for the strange delay with which evaluation error messages where delivered.