From f02c48a9097bd2278aad065d9434be91d1c7c06b Mon Sep 17 00:00:00 2001
From: Dave Smith <dizzyd@dizzyd.com>
Date: Thu, 17 Dec 2009 07:26:54 -0700
Subject: [PATCH] Adding simple checks for necessary version of ERTS + Reltool

---
 src/rebar.erl | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/src/rebar.erl b/src/rebar.erl
index 0e92731..1e44293 100644
--- a/src/rebar.erl
+++ b/src/rebar.erl
@@ -27,6 +27,26 @@
 -export([main/1]).
 
 main(Args) ->
+    %% HACK: Make sure the caller is running w/ r13b03 and reltool >= 0.5.2
+    case erlang:system_info(version) < "5.7.4" of
+        true ->
+            io:format("Rebar requires at least erts 5.7.4; this VM is using ~s\n",
+                      [erlang:system_info(version)]),
+            halt(1);
+        false ->
+            ok
+    end,
+
+    ReltoolVsn = filename:basename(code:lib_dir(reltool)),
+    case ReltoolVsn < "reltool-0.5.2" of
+        true ->
+            io:format("Rebar requires at least reltool-0.5.2; this VM is using ~s\n",
+                      [ReltoolVsn]),
+            halt(1);
+        false ->
+            ok
+    end,
+    
     case catch(rebar_core:run(Args)) of
         ok ->
             ok;