From 93ae90de0f118417682ff532935675e4867df9db Mon Sep 17 00:00:00 2001
From: Will Dietz <w@wdtz.org>
Date: Sat, 26 May 2018 14:04:41 -0500
Subject: [PATCH] eval.cc: add message to static_assert, message can be omitted
 w/c++17

---
 src/libexpr/eval.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 2473157b3..7c8978000 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -307,7 +307,7 @@ EvalState::EvalState(const Strings & _searchPath, ref<Store> store)
 
     assert(gcInitialised);
 
-    static_assert(sizeof(Env) == 16);
+    static_assert(sizeof(Env) == 16, "environment must be 16 bytes");
 
     /* Initialise the Nix expression search path. */
     if (!settings.pureEval) {