02/06: offload: Warn about the lack of zlib support.

[Ludovic Courtès]

civodul pushed a commit to branch master
in repository guix.

commit 0b72475301e20521e0dd9fc22881eaab4a7fe170
Author: Ludovic Courtès <address@hidden>
Date:   Thu Dec 1 21:49:16 2016 +0100

    offload: Warn about the lack of zlib support.
    
    * guix/scripts/offload.scm (guix-offload): Print a warning when
    'zlib-support?' returns false.
---
 guix/scripts/offload.scm |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/guix/scripts/offload.scm b/guix/scripts/offload.scm
index 1d60f65..4f6de0b 100644
--- a/guix/scripts/offload.scm
+++ b/guix/scripts/offload.scm
@@ -24,6 +24,7 @@
   #:use-module (ssh popen)
   #:use-module (ssh dist)
   #:use-module (ssh dist node)
+  #:use-module (ssh version)
   #:use-module (guix config)
   #:use-module (guix records)
   #:use-module (guix store)
@@ -634,6 +635,12 @@ allowed on MACHINE."
   (and=> (passwd:dir (getpw (getuid)))
          (cut setenv "HOME" <>))
 
+  ;; We rely on protocol-level compression from libssh to optimize large data
+  ;; transfers.  Warn if it's missing.
+  (unless (zlib-support?)
+    (warning (_ "Guile-SSH lacks zlib support"))
+    (warning (_ "data transfers will *not* be compressed!")))
+
   (match args
     ((system max-silent-time print-build-trace? build-timeout)
      (let ((max-silent-time    (string->number max-silent-time))