doc: contributing: Recommand option --keyring of 'guix git authenticate'.

* doc/contributing.texi (Building from Git): Remove mention to fetch the
keyring branch from origin and replace by the option '--keyring'.

Change-Id: I32fdf688329bb874210064ebfc814b14fdb35d17
Signed-off-by: Maxim Cournoyer <maxim@guixotic.coop>

1 files changed, 3 insertions, 3 deletions

diff --git a/doc/contributing.texi b/doc/contributing.texi
index 0863bf5c2f4..65221505604 100644
--- a/doc/contributing.texi
+++ b/doc/contributing.texi
@@ -153,8 +153,8 @@ and OpenPGP fingerprint of the @dfn{channel introduction}
 @c The commit and fingerprint below must match those of the channel
 @c introduction in '%default-channels'.
 @example
-git fetch origin keyring:keyring
-guix git authenticate 9edb3f66fd807b096b48283debdcddccfea34bad \
+guix git authenticate -k origin/keyring \
+   9edb3f66fd807b096b48283debdcddccfea34bad \
   "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA"
 @end example
 
@@ -277,7 +277,7 @@ From there on, you can authenticate all the commits included in your
 checkout by running:
 
 @example
-guix git authenticate \
+guix git authenticate -k origin/keyring \
   9edb3f66fd807b096b48283debdcddccfea34bad \
   "BBB0 2DDF 2CEA F6A8 0D1D  E643 A2A0 6DF2 A33A 54FA"
 @end example