diff --git a/guix/build-system/python.scm b/guix/build-system/python.scm index e8af9f8146..37108650d0 100644 --- a/guix/build-system/python.scm +++ b/guix/build-system/python.scm @@ -1,5 +1,5 @@ ;;; GNU Guix --- Functional package management for GNU -;;; Copyright © 2013, 2014 Ludovic Courtès +;;; Copyright © 2013, 2014, 2015 Ludovic Courtès ;;; Copyright © 2013 Andreas Enge ;;; Copyright © 2013 Nikita Karetnikov ;;; @@ -76,7 +76,10 @@ prepended to the name." (substring name (string-length old-prefix)) name)))) (arguments - (let ((arguments (package-arguments p))) + (let ((arguments (package-arguments p)) + (python (if (promise? python) + (force python) + python))) (if (member #:python arguments) (substitute-keyword-arguments arguments ((#:python p) python)) (append arguments `(#:python ,python))))) @@ -86,7 +89,11 @@ prepended to the name." p))) (define package-with-python2 - (cut package-with-explicit-python <> (default-python2) "python-" "python2-")) + ;; Note: delay call to 'default-python2' until after the 'arguments' field + ;; of packages is accessed to avoid a circular dependency when evaluating + ;; the top-level of (gnu packages python). + (cut package-with-explicit-python <> (delay (default-python2)) + "python-" "python2-")) (define* (lower name #:key source inputs native-inputs outputs system target