From 613fca01486e47dee9364a2fd86b5f5e77fe23c8 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Wed, 7 Dec 2022 22:14:44 +0900
Subject: [PATCH] [Bug #19189] Fallback to the default "pkg-config"

---
 lib/mkmf.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index e94733c6357afa..0fbc1cc2e5c80a 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -1866,7 +1866,7 @@ def pkg_config(pkg, *options)
     if pkgconfig = with_config("#{pkg}-config") and find_executable0(pkgconfig)
       # if and only if package specific config command is given
     elsif ($PKGCONFIG ||=
-           (pkgconfig = with_config("pkg-config", RbConfig::CONFIG["PKG_CONFIG"])) &&
+           (pkgconfig = with_config("pkg-config") {config_string("PKG_CONFIG") || "pkg-config"}) &&
            find_executable0(pkgconfig) && pkgconfig) and
         xsystem([*envs, $PKGCONFIG, "--exists", pkg])
       # default to pkg-config command