Hi Laurence, Not an expert on GUIX_PACKAGE_PATH semantics, but they aren't relevant ‘yet’. You need to first fix this syntax error you might've missed:
>$ guix build my-packages/zasm >/home/laurence/src/my-channel/my-packages/zasm.scm:2:2: warning: >expected keyword arg DEFINE-MODULE takes #:keyword arguments, e.g., (define-module (my-packages zasm) #:use-module (guix packages) #:use-module (guix download) …) Kind regards, T G-R Sent on the go. Excuse or enjoy my brevity.