Disable `-flto` on CentOS 6

rebar.config

@@ -7,13 +7,15 @@
 ]}.
 
 {port_env, [
+    {".*", "FLTO_FLAG", "-flto"},
+
     {"(linux|solaris|freebsd|netbsd|openbsd|dragonfly|darwin|gnu)",
-        "CFLAGS", "$CFLAGS -Ic_src/ -g -Wall -flto -Werror -O3"},
+        "CFLAGS", "$CFLAGS -Ic_src/ -g -Wall $FLTO_FLAG -Werror -O3"},
     {"(linux|solaris|freebsd|netbsd|openbsd|dragonfly|darwin|gnu)",
-        "CXXFLAGS", "$CXXFLAGS -Ic_src/ -g -Wall -flto -Werror -O3"},
+        "CXXFLAGS", "$CXXFLAGS -Ic_src/ -g -Wall $FLTO_FLAG -Werror -O3"},
 
     {"(linux|solaris|freebsd|netbsd|openbsd|dragonfly|darwin|gnu)",
-        "LDFLAGS", "$LDFLAGS -flto -lstdc++"},
+        "LDFLAGS", "$LDFLAGS $FLTO_FLAG -lstdc++"},
 
     %% OS X Leopard flags for 64-bit
     {"darwin9.*-64$", "CXXFLAGS", "-m64"},

rebar.config.script

@@ -9,10 +9,21 @@ ErlOpts = if not HaveEQC -> []; true ->
     [{d, 'HAVE_EQC'}]
 end,
 
-case lists:keyfind(erl_opts, 1, CONFIG) of
+Config1 = case lists:keyfind(erl_opts, 1, CONFIG) of
     {erl_opts, Opts} ->
         NewOpts = {erl_opts, Opts ++ ErlOpts},
         lists:keyreplace(erl_opts, 1, CONFIG, NewOpts);
     false ->
         CONFIG ++ [{erl_opts, ErlOpts}]
+end,
+
+
+case os:cmd("rpm -q --queryformat '%{VERSION}' centos-release") of
+    "6\n" ->
+        {port_env, PortEnv} = lists:keyfind(port_env, 1, Config1),
+        NewFlag = {".*", "FLTO_FLAG", ""},
+        NewPortEnv = lists:keyreplace("FLTO_FLAG", 2, PortEnv, NewFlag),
+        lists:keyreplace(port_env, 1, Config1, {port_env, NewPortEnv});
+    _ ->
+        Config1
 end.