libstore: deprecate the build-hook setting

implementing a build hook is pretty much impossible without either being
a nix, or blindly forwarding the important bits of all build requests to
some kind of nix. we've found no uses of build-hook in the wild, and the
build-hook protocol (apart from being entirely undocumented) is not able
to convey any kind of versioning information between hook and daemon. if
we want to upgrade this infrastructure (which we do), this must not stay

Change-Id: I1ec4976a35adf8105b8ca9240b7984f8b91e147e

1 files changed, 6 insertions, 2 deletions

diff --git a/src/libstore/globals.hh b/src/libstore/globals.hh
index 1aeb462d4..4709ac715 100644
--- a/src/libstore/globals.hh
+++ b/src/libstore/globals.hh
@@ -248,14 +248,18 @@ public:
         )",
         {"build-timeout"}};
 
-    Setting<Strings> buildHook{this, {}, "build-hook",
+    Setting<Strings> buildHook{
+        AbstractSetting::deprecated_t{},
+        this, {}, "build-hook",
         R"(
           The path to the helper program that executes remote builds.
 
           Lix communicates with the build hook over `stdio` using a custom protocol to request builds that cannot be performed directly by the Nix daemon.
           The default value is the internal Lix binary that implements remote building.
 
-          > **Important**
+          > **Warning**
+          >
+          > This setting is deprecated and will be removed in a future version of Lix.
           >
           > Change this setting only if you really know what you’re doing.
         )"};