Hi, TL;DR: How do I get my in-development version of guix into the VM build with this version? I made KDE Plasma start up in a VM by adding tons of packages to the system declaration (to be on the save side). Now for finishing and providing a nice service declaration I need to strip this list of packages down to the bare minimum. Since a vm (sharing the host store) is unacceptable sloooooow, I've build a vm-image using my development environment ("./pre-inst-env guix system vm-image …"). Now within the VM-image there is a different version of guix installed than the in-development one I used for building the VM. Of course the former one does not know any of the packages I've just added. So I can't not just run "guix system reconfigure …". After some luckless tries I assume the easiest solution would be to get my in-development version of guix into the VM. How to achieve this? What I've tried: 0) Using a VM sharing the host store: Here starting Plasma takes 2 minutes, which is not acceptable for series of tests. 1) My first idea was to share my development directory with the VM and run "./pre-inst-env guix system reconfigure …" from within the VM. This failed with   ./pre-inst-env: …/scripts/guix: /gnu/store/…-profile/bin/guile: bad interpreter: No such file or directory Well, yes. within the VM, my external profile is not available :-( 2) Changing the patch in …/scripts/guix into /run/current-system/profile/bin/guile failed with     /gnu/store/…-libgcrypt-1.8.1/lib/libgcrypt -- Regards Hartmut Goebel | Hartmut Goebel | h.goebel@crazy-compilers.com | | www.crazy-compilers.com | compilers which you thought are impossible |