Chez Scheme upgrade fatally criples pack

[stephen-smith]

Recently upgraded chezscheme from the version in Debian Bookworm to the version current in Debian Trixie.

Now, all operations, including uninstall fail:

% pack uninstall
Exception: incompatible fasl-object version 0.0.0-pre-release.73 found in /home/bss/.pack/install/pack/fa686af45720d8117d06482cf5054280a7847142/pack_app/pack.so

I don't really expect a fix for this, but it might be useful to document the "correct" path forward here... I plan to delete $PACK_DIR and reinstall.

[buzden]

This is a known issue induced by chez (and, actually, racket too), and definitely should be documented. Maybe, we can change runner scripts generated by pack to check chez version and to advise correct actions in case of inconsistency, but we should be accurate when any other codegens are used.

When deleting pack dir, don't forget to backup user/pack.toml if it contains your personal settings