Hi, Michael Mausler skribis: > I tried guix pull another time which failed with a similar error, so I > tried with the --fallback flag and that worked. Thanks for getting back to > me. Do you still have the output that appeared above the backtrace? There should be a clue as to why downloading Graphviz failed. For the record, the two substitutes appear to be available: --8<---------------cut here---------------start------------->8--- $ wget -qO - https://ci.guix.gnu.org/nar/lzip/bi9hjvhcgr5rc0r29wmb18xxk4cgphx8-graphviz-2.42.3 | lzip -d | wc -c 8372744 $ wget -qO - https://ci.guix.gnu.org/nar/lzip/a2j5znslnafdydcrx9jqpr6n25a3k6vf-graphviz-2.42.3-doc | lzip -d | wc -c 5724672 --8<---------------cut here---------------end--------------->8--- Thanks, Ludo’.