From 0ff3e3aa9bea8c82c921db88fc03cb7361b886f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Sat, 20 Apr 2013 10:53:31 +0200
Subject: [PATCH] daemon: Gracefully handle cases where the daemon does not
 return a status code.

* guix/store.scm (process-stderr): Check for EOF before doing (read-int p).
---
 guix/store.scm | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/guix/store.scm b/guix/store.scm
index b1b60babf0..b82588b2a0 100644
--- a/guix/store.scm
+++ b/guix/store.scm
@@ -336,7 +336,10 @@ encoding conversion errors."
              #f))
           ((= k %stderr-error)
            (let ((error  (read-latin1-string p))
-                 (status (if (>= (nix-server-minor-version server) 8)
+                 ;; Currently the daemon fails to send a status code for early
+                 ;; errors like DB schema version mismatches, so check for EOF.
+                 (status (if (and (>= (nix-server-minor-version server) 8)
+                                  (not (eof-object? (lookahead-u8 p))))
                              (read-int p)
                              1)))
              (raise (condition (&nix-protocol-error