From c134da2196f4cf7e4e5acb46ad1f3c453e48babc Mon Sep 17 00:00:00 2001
From: Michael Klishin <michael@clojurewerkz.org>
Date: Sat, 21 Dec 2019 18:27:39 +0300
Subject: [PATCH] Adapt to stricter unused variable check in OTP 23

See [1] for context.

1. https://bugs.erlang.org/browse/ERL-1113
---
 src/r3_hex_tarball.erl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/r3_hex_tarball.erl b/src/r3_hex_tarball.erl
index fb8c7986..63b61f8b 100644
--- a/src/r3_hex_tarball.erl
+++ b/src/r3_hex_tarball.erl
@@ -201,7 +201,7 @@ do_unpack(Files, Output) ->
 finish_unpack({error, _} = Error) ->
     Error;
 finish_unpack(#{metadata := Metadata, files := Files, output := Output}) ->
-    _Version = maps:get("VERSION", Files),
+    true = maps:is_key("VERSION", Files),
     Checksum = decode_base16(maps:get("CHECKSUM", Files)),
     ContentsBinary = maps:get("contents.tar.gz", Files),
     case unpack_tarball(ContentsBinary, Output) of