02/05: herd: Define 'shepherd-message-port'.

[guix-commits]

civodul pushed a commit to branch master
in repository guix.

commit 6aeae5b90b9513d316141c0131fd43c76a200f63
Author: Ludovic Courtès <address@hidden>
Date:   Fri Oct 18 22:37:20 2019 +0200

    herd: Define 'shepherd-message-port'.
    
    * gnu/services/herd.scm (shepherd-message-port): New variable.
    (display-message): Use it instead of 'current-error-port'.
---
 gnu/services/herd.scm | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/gnu/services/herd.scm b/gnu/services/herd.scm
index 2207b2d..112a7dc 100644
--- a/gnu/services/herd.scm
+++ b/gnu/services/herd.scm
@@ -25,6 +25,7 @@
   #:use-module (srfi srfi-35)
   #:use-module (ice-9 match)
   #:export (%shepherd-socket-file
+            shepherd-message-port
 
             shepherd-error?
             service-not-found-error?
@@ -140,8 +141,12 @@ does not denote an error."
     (#f                                           ;not an error
      #t)))
 
+(define shepherd-message-port
+  ;; Port where messages coming from shepherd are printed.
+  (make-parameter (current-error-port)))
+
 (define (display-message message)
-  (format (current-error-port) "shepherd: ~a~%" message))
+  (format (shepherd-message-port) "shepherd: ~a~%" message))
 
 (define* (invoke-action service action arguments cont)
   "Invoke ACTION on SERVICE with ARGUMENTS.  On success, call CONT with the