Demo cairo clock needs little modification, why?

[bigos]

https://github.com/bigos/execnik/blob/4ad4b38433bb80d39e03077a25954f554ad3f487/execnik.lisp#L93

I had to comment out the above to make your example work.

I wonder why. I had similar issue in another experiment where I blindly followed C example. Is it possible that Lisp garbage collection also destroys it?

[Ferada]

Yes. That's not really related to Lisp GC, it simply should not be destroyed since it's still in use in the widget that's being drawn on, though the documentation doesn't explicitly say that I suppose.

[stacksmith]

Funny: I did the same exact thing yesterday...