repl: Add "-q".

* guix/scripts/repl.scm (%options, show-help): Add "-q".
(guix-repl): Add 'user-config' and use it.  Honor 'ignore-dot-guile?'.

doc/guix.texi

@@ -8008,6 +8008,10 @@ Add @var{directory} to the front of the package module search path
 
 This allows users to define their own packages and make them visible to
 the command-line tool.
+
+@item -q
+Inhibit loading of the @file{~/.guile} file.  By default, that
+configuration file is loaded when spawning a @code{guile} REPL.
 @end table
 
 @c *********************************************************************

guix/scripts/repl.scm

@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2018, 2019 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2020 Simon Tournier <zimon.toutoune@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -55,6 +55,9 @@ (define %options
         (option '("listen") #t #f
                 (lambda (opt name arg result)
                   (alist-cons 'listen arg result)))
+        (option '(#\q) #f #f
+                (lambda (opt name arg result)
+                  (alist-cons 'ignore-dot-guile? #t result)))
         (find (lambda (option)
                 (member "load-path" (option-names option)))
               %standard-build-options)))
@@ -67,6 +70,8 @@ (define (show-help)
   -t, --type=TYPE        start a REPL of the given TYPE"))
   (display (G_ "
       --listen=ENDPOINT  listen ENDPOINT instead of standard I/O"))
+  (display (G_ "
+  -q                     inhibit loading of ~/.guile"))
   (newline)
   (display (G_ "
   -L, --load-path=DIR    prepend DIR to the package module search path"))
@@ -139,6 +144,11 @@ (define opts
                   (leave (G_ "~A: extraneous argument~%") arg))
                 %default-options))
 
+  (define user-config
+    (and=> (getenv "HOME")
+           (lambda (home)
+             (string-append home "/.guile"))))
+
   (with-error-handling
     (let ((type (assoc-ref opts 'type)))
       (call-with-connection (assoc-ref opts 'listen)
@@ -148,11 +158,11 @@ (define opts
              (save-module-excursion
               (lambda ()
                 (set-current-module user-module)
-                (and=> (getenv "HOME")
-                       (lambda (home)
-                         (let ((guile (string-append home "/.guile")))
-                           (when (file-exists? guile)
-                             (load guile)))))
+                (when (and (not (assoc-ref opts 'ignore-dot-guile?))
+                           user-config
+                           (file-exists? user-config))
+                  (load user-config))
+
                 ;; Do not exit repl on SIGINT.
                 ((@@ (ice-9 top-repl) call-with-sigint)
                  (lambda ()