From c643db6bcad0d8aa01cf15506d307376f3ed6307 Mon Sep 17 00:00:00 2001
From: "Zaiming (Stone) Shi" <zmstone@gmail.com>
Date: Mon, 31 Jan 2022 16:27:31 +0100
Subject: [PATCH] build: move otp version check to rebar.config.erl

---
 Makefile                                |  1 -
 rebar.config.erl                        | 17 +++++++++++++++++
 scripts/fail-on-old-otp-version.escript | 12 ------------
 3 files changed, 17 insertions(+), 13 deletions(-)
 delete mode 100755 scripts/fail-on-old-otp-version.escript

diff --git a/Makefile b/Makefile
index c4ede011c..e03d91ae9 100644
--- a/Makefile
+++ b/Makefile
@@ -34,7 +34,6 @@ all: $(REBAR) $(PROFILES)
 
 .PHONY: ensure-rebar3
 ensure-rebar3:
-	@$(SCRIPTS)/fail-on-old-otp-version.escript
 	@$(SCRIPTS)/ensure-rebar3.sh $(REBAR_VERSION)
 
 .PHONY: ensure-hex
diff --git a/rebar.config.erl b/rebar.config.erl
index 7a0d5e26f..c73f77b25 100644
--- a/rebar.config.erl
+++ b/rebar.config.erl
@@ -3,6 +3,7 @@
 -export([do/2]).
 
 do(Dir, CONFIG) ->
+    ok = assert_otp(),
     case iolist_to_binary(Dir) of
         <<".">> ->
             C1 = deps(CONFIG),
@@ -12,6 +13,22 @@ do(Dir, CONFIG) ->
             CONFIG
     end.
 
+assert_otp() ->
+    Oldest = 23,
+    Latest = 24,
+    OtpRelease = list_to_integer(erlang:system_info(otp_release)),
+    case OtpRelease < Oldest orelse OtpRelease > Latest of
+        true ->
+            io:format(standard_error, "ERROR: Erlang/OTP version ~p found. min=~p, recommended=~p~n",
+                      [OtpRelease, Oldest, Latest]),
+            halt(1);
+        false when OtpRelease =/= Latest ->
+            io:format("WARNING: Erlang/OTP version ~p found, recommended==~p~n",
+                      [OtpRelease, Latest]);
+        false ->
+            ok
+    end.
+
 bcrypt() ->
     {bcrypt, {git, "https://github.com/emqx/erlang-bcrypt.git", {branch, "0.6.0"}}}.
 
diff --git a/scripts/fail-on-old-otp-version.escript b/scripts/fail-on-old-otp-version.escript
deleted file mode 100755
index 0e4cd2a1b..000000000
--- a/scripts/fail-on-old-otp-version.escript
+++ /dev/null
@@ -1,12 +0,0 @@
-#!/usr/bin/env escript
-
-main(_) ->
-    OtpRelease = list_to_integer(erlang:system_info(otp_release)),
-    case OtpRelease < 21 of
-        true ->
-            io:format(standard_error, "ERROR: Erlang/OTP version ~p found. required_min=21, recommended=23~n", [OtpRelease]),
-            halt(1);
-        false ->
-            ok
-    end.
-