Hello Guix! Starting from commit 4f621a2b003e85d480999e4d0630e9dc3de85bc3, we require Guile >= 2.2.6. Since (srfi srfi-71) was added in Guile 2.2.4, I suggest using it instead of the more clunky (srfi srfi-11) ‘let-values’. We can gradually migrate code. Note that (guix build utils), (guix build gnu-build-system), and probably a few other (guix build …) modules that are used early during bootstrap, where Guile 2.0 is used, cannot migrate. Ludo’.