281/285: inferior: Add 'inferior-package-provenance'.

[guix-commits]

kkebreau pushed a commit to branch wip-gnome3.34
in repository guix.

commit e5701e4bbe5503fd3038ab2202d48db64bdb2d0a
Author: Ludovic Courtès <address@hidden>
Date:   Sun Dec 29 17:35:56 2019 +0100

    inferior: Add 'inferior-package-provenance'.
    
    * guix/inferior.scm (inferior-package-provenance): New procedure.
---
 guix/inferior.scm | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/guix/inferior.scm b/guix/inferior.scm
index 71dae89..c4969cd 100644
--- a/guix/inferior.scm
+++ b/guix/inferior.scm
@@ -82,6 +82,7 @@
             inferior-package-native-search-paths
             inferior-package-transitive-native-search-paths
             inferior-package-search-paths
+            inferior-package-provenance
             inferior-package-derivation
 
             inferior-package->manifest-entry
@@ -416,6 +417,19 @@ package."
 (define inferior-package-transitive-native-search-paths
   (cut %inferior-package-search-paths <> 
'package-transitive-native-search-paths))
 
+(define (inferior-package-provenance package)
+  "Return a \"provenance sexp\" for PACKAGE, an inferior package.  The result
+is similar to the sexp returned by 'package-provenance' for regular packages."
+  (inferior-package-field package
+                          '(let* ((describe
+                                   (false-if-exception
+                                    (resolve-interface '(guix describe))))
+                                  (provenance
+                                   (false-if-exception
+                                    (module-ref describe
+                                                'package-provenance))))
+                             (or provenance (const #f)))))
+
 (define (proxy client backend)                    ;adapted from (guix ssh)
   "Proxy communication between CLIENT and BACKEND until CLIENT closes the
 connection, at which point CLIENT is closed (both CLIENT and BACKEND must be