refresh: Account for overlapping updater coverage.

* guix/scripts/refresh.scm (list-updaters-and-exit): Do not assume updater
predicates are disjoint.  Track covered packages directly.

1 files changed, 8 insertions, 8 deletions

diff --git a/guix/scripts/refresh.scm b/guix/scripts/refresh.scm
index 60e822b16b..1d86f949c8 100644
--- a/guix/scripts/refresh.scm
+++ b/guix/scripts/refresh.scm
@@ -179,24 +179,24 @@ specified with `--select'.\n"))
 
   (let* ((packages (fold-packages cons '()))
          (total    (length packages)))
-    (define covered
-      (fold (lambda (updater covered)
-              (let ((matches (count (upstream-updater-predicate updater)
-                                    packages)))
+    (define uncovered
+      (fold (lambda (updater uncovered)
+              (let ((matches (filter (upstream-updater-predicate updater)
+                                     packages)))
                 ;; TRANSLATORS: The parenthetical expression here is rendered
                 ;; like "(42% coverage)" and denotes the fraction of packages
                 ;; covered by the given updater.
                 (format #t (G_ "  - ~a: ~a (~2,1f% coverage)~%")
                         (upstream-updater-name updater)
                         (G_ (upstream-updater-description updater))
-                        (* 100. (/ matches total)))
-                (+ covered matches)))
-            0
+                        (* 100. (/ (length matches) total)))
+                (lset-difference eq? uncovered matches)))
+            packages
             (force %updaters)))
 
     (newline)
     (format #t (G_ "~2,1f% of the packages are covered by these updaters.~%")
-            (* 100. (/ covered total))))
+            (* 100. (/ (- total (length uncovered)) total))))
   (exit 0))
 
 (define (warn-no-updater package)