Znavko, Guix's operating-system is a record. Records are just key-value pair collections. Some keys have default values, but there's no need to remove anything when you simply want to replace the default. znavko--- via 写道: > I just want to unset 'firmware' or make it totally empty. Pass the empty list as its value: (operating-system ... (firmware (list)) ; or '() if you like that ...) Kind regards, T G-R