Hi Guixers, when I did a guix package -u and also when I checked it beforehand with guix package --upgrade --dry-run if 100 % derivations are available ( I did this the last 4 times) nevertheless the music notation program "MuseScore" had to be built on my laptop. With my 64 GB CPU it took 1 hour (I did it twice). But why is it built on my laptop if the derivations are 100 % available and I was not informed that e.g. MuseScore will be built at my laptop. The same with the package "calibre". Gottfried