gexp: Aggregate outputs of compound gexps.

* guix/gexp.scm (gexp-outputs)[add-reference-output]: Recurse into
  lists.
* tests/gexp.scm ("output list + ungexp-splicing list, combined gexps"):
  New test.

1 files changed, 3 insertions, 3 deletions

diff --git a/guix/gexp.scm b/guix/gexp.scm
index a8349c7d6e..1f64cf75ae 100644
--- a/guix/gexp.scm
+++ b/guix/gexp.scm
@@ -314,12 +314,12 @@ references."
        (cons name result))
       ((? gexp? exp)
        (append (gexp-outputs exp) result))
+      ((lst ...)
+       (fold-right add-reference-output result lst))
       (_
        result)))
 
-  (fold-right add-reference-output
-              '()
-              (gexp-references exp)))
+  (add-reference-output (gexp-references exp) '()))
 
 (define* (gexp->sexp exp #:key
                      (system (%current-system))