I pushed a workaround as e79281be105b16153c375af5506db31fd1e32698, though more work is still needed to fully understand what’s happening. Note that you can test things like this: --8<---------------cut here---------------start------------->8--- $ ./pre-inst-env guile GNU Guile 2.2.5 Copyright (C) 1995-2019 Free Software Foundation, Inc. Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'. This program is free software, and you are welcome to redistribute it under certain conditions; type `,show c' for details. Enter `,help' for help. scheme@(guile-user)> ,use(guix store) scheme@(guile-user)> (use-modules (gnu ci) (ice-9 match)) scheme@(guile-user)> (define store (open-connection)) scheme@(guile-user)> (define jobs (hydra-jobs store '((systems "x86_64-linux" "i686-linux")))) evaluating for 'x86_64-linux' (heap size: 35.0 MiB)... random seed for tests: 1562154761 evaluating for 'i686-linux' (heap size: 467.0 MiB)... --8<---------------cut here---------------end--------------->8--- Ludo’.