package: Preserve the installed package output when upgrading.

* guix/scripts/package.scm (guix-package)[find-package]: Add optional
  parameter `output'.  Use it.
  [process-actions]: When computing UPGRADE, pass OUTPUT to
  `find-package'.

1 files changed, 6 insertions, 4 deletions

diff --git a/guix/scripts/package.scm b/guix/scripts/package.scm
index b970c2b7b9..1d17911dc1 100644
--- a/guix/scripts/package.scm
+++ b/guix/scripts/package.scm
@@ -520,10 +520,11 @@ Install, remove, or upgrade PACKAGES in a single transaction.\n"))
           ((_ version pkgs ...) pkgs)
           (#f '()))))
 
-  (define (find-package name)
+  (define* (find-package name #:optional (output "out"))
     ;; Find the package NAME; NAME may contain a version number and a
     ;; sub-derivation name.  If the version number is not present,
-    ;; return the preferred newest version.
+    ;; return the preferred newest version.  If the sub-derivation name is not
+    ;; present, use OUTPUT.
     (define request name)
 
     (define (ensure-output p sub-drv)
@@ -535,7 +536,7 @@ Install, remove, or upgrade PACKAGES in a single transaction.\n"))
 
     (let*-values (((name sub-drv)
                    (match (string-rindex name #\:)
-                     (#f    (values name "out"))
+                     (#f    (values name output))
                      (colon (values (substring name 0 colon)
                                     (substring name (+ 1 colon))))))
                   ((name version)
@@ -687,7 +688,8 @@ Install, remove, or upgrade PACKAGES in a single transaction.\n"))
                                              (and (any (cut regexp-exec <> name)
                                                        upgrade-regexps)
                                                   (upgradeable? name version path)
-                                                  (find-package name)))
+                                                  (find-package name
+                                                                (or output "out"))))
                                             (_ #f))
                                            installed))))
                (install  (append