daemon: Really enable automatic deduplication by default.

* nix/nix-daemon/guix-daemon.cc (main): Set 'autoStoreOptimise' to
  true.  Add 'printMsg' call.
* tests/derivations.scm ("identical files are deduplicated"): New test.

1 files changed, 7 insertions, 0 deletions

diff --git a/nix/nix-daemon/guix-daemon.cc b/nix/nix-daemon/guix-daemon.cc
index 0bb9f7559c..0309743de1 100644
--- a/nix/nix-daemon/guix-daemon.cc
+++ b/nix/nix-daemon/guix-daemon.cc
@@ -249,6 +249,9 @@ main (int argc, char *argv[])
   settings.useChroot = false;
 #endif
 
+  /* Turn automatic deduplication on by default.  */
+  settings.autoOptimiseStore = true;
+
   argvSaved = argv;
 
   try
@@ -326,6 +329,10 @@ main (int argc, char *argv[])
 #endif
 
       printMsg (lvlDebug,
+		format ("automatic deduplication set to %1%")
+		% settings.autoOptimiseStore);
+
+      printMsg (lvlDebug,
 		format ("listening on `%1%'") % settings.nixDaemonSocketFile);
 
       run (nothing);