services: base: Add extra-env support to guix-configuration.

* gnu/services/base.scm (<guix-configuration>)[extra-env]: New field.
(guix-shepherd-service): Honor it.
* doc/guix.texi (Base Services): Document it.

1 files changed, 4 insertions, 0 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 293c3016aa..e337945ba7 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -18482,6 +18482,10 @@ herd set-http-proxy guix-daemon
 @item @code{tmpdir} (default: @code{#f})
 A directory path where the @command{guix-daemon} will perform builds.
 
+@item @code{extra-env} (default: @code{'()})
+Environment variables to be set before starting the daemon, as a list of
+@code{key=value} strings.
+
 @end table
 @end deftp