Hi Ludo, > --8<---------------cut here---------------start------------->8--- > $ time guix environment --ad-hoc r-learnr --search-paths > export PATH="/gnu/store/n4wxbmqpafjfyawrla8xymzzdm5hxwph-profile/bin${PATH:+:}$PATH" > > real 0m11.328s > user 0m20.155s > sys 0m0.172s > $ time ./pre-inst-env guix environment --ad-hoc r-learnr --search-paths > export PATH="/gnu/store/if6z77la3mx0qdzvcyl4qv9i5cyp48i0-profile/bin${PATH:+:}$PATH" > > real 0m4.602s > user 0m6.189s > sys 0m0.136s > --8<---------------cut here---------------end--------------->8--- that’s awesome and brings me much closer to my goal of running all applications inside a `guix environment` container for reproducibility. Including the protocol fixes from #41720 I’m now down to ~30s from ~50s, which may be called somewhat usable. Obviously I’d be very interested in further speedups. Thanks, Lars