Subject: Add link to 'pre-inst-env' from 'installing from git' docs

From: Emma Turner <[email-masked]>
Date: Sun, 18 Sep 2022 13:47:23 +0200 (CEST)

>From 4849857fcf13f8de572d030cd15defd1f2b84768 Mon Sep 17 00:00:00 2001
From: Emma Turner <[email-masked]>
Date: Sun, 18 Sep 2022 12:40:17 +0100
Subject: [PATCH] doc: link pre-inst-env from building from git docs

---
 doc/contributing.texi | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/doc/contributing.texi b/doc/contributing.texi
index 17a54f94cc..d4cd57141d 100644
--- a/doc/contributing.texi
+++ b/doc/contributing.texi
@@ -159,6 +159,14 @@ checkout by running:
 make authenticate
 @end example
 
+If you get an error of @code{guix: command not found}, then you can refer
+to the new instance you built above, by running the following
+(see @pxref{Running Guix Before It Is Installed}):
+
+@example
+./pre-inst-env make authenticate
+@end example
+
 The first run takes a couple of minutes, but subsequent runs are faster.
 
 Or, when your configuration for your local Git repository doesn't match
-- 
2.36.1