@lukego, thanks for your PR! By analyzing the history of the files in this pull request, we identified @DamienCassou, @fpletz and @globin to be potential reviewers.

This seems to be only a partial fix. On the one hand it permits me to run pharo-launcher but on the other hand there is a different error when trying to run the latest Pharo image by downloading it and running pharo-spur-vm-x Pharo-50771.image.

nixpkgs is bundling two Pharo VMs and it could be that the traditional one is working while the new Spur VM is still broken. I'll dig a little more.

@domenkozar I would recommend merging this PR in order to fix the current Pharo version and make the test case merged in #24597 pass. This will put everything into a basically okay state: default Pharo VM in NixOS will work but it will still be a bit old.

I am working with Pharo upstream to refresh things more completely. The problem is that not all of the necessary components have official releases at the moment and everybody is running versions served up from the Pharo CI server which is not doing this in a reproducible/nix-friendly way.

@lukego that makes sense, thanks!

GCC generating position independent code using EBX for doing a call without spilling/unspilling its value.