Subject: [bug#40077] [PATCH 2/4] inferior: Adjust to protocol (0 1).

From: Ludovic Courtès <[email-masked]>
Date: Sun, 15 Mar 2020 18:15:05 +0100

* guix/inferior.scm (port->inferior): For protocol (0 x ...), where x >= 1,
send the (() repl-version ...) form.
---
 guix/inferior.scm | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/guix/inferior.scm b/guix/inferior.scm
index 6b685ece30..ec8ff8ddbe 100644
--- a/guix/inferior.scm
+++ b/guix/inferior.scm
@@ -159,6 +159,15 @@ inferior."
      (letrec ((result (inferior 'pipe pipe close (cons 0 rest)
                                 (delay (%inferior-packages result))
                                 (delay (%inferior-package-table result)))))
+
+       ;; For protocol (0 1) and later, send the protocol version we support.
+       (match rest
+         ((n _ ...)
+          (when (>= n 1)
+            (send-inferior-request '(() repl-version 0 1) result)))
+         (_
+          #t))
+
        (inferior-eval '(use-modules (guix)) result)
        (inferior-eval '(use-modules (gnu)) result)
        (inferior-eval '(use-modules (ice-9 match)) result)
-- 
2.25.1