fix: include the recipe's lib path in $LDFLAGS

Fixes #118

lib/mini_portile2/mini_portile.rb

@@ -238,14 +238,26 @@ def activate
       end
     end
 
-    # rely on LDFLAGS when cross-compiling
-    if File.exist?(lib_path) && (@host != @original_host)
-      full_path = File.expand_path(lib_path)
+    if File.exist?(lib_path)
+      # rely on LDFLAGS when cross-compiling
+      if (@host != @original_host)
+        full_path = File.expand_path(lib_path)
 
-      old_value = ENV.fetch("LDFLAGS", "")
+        old_value = ENV.fetch("LDFLAGS", "")
 
-      unless old_value.include?(full_path)
-        ENV["LDFLAGS"] = "-L#{full_path} #{old_value}".strip
+        unless old_value.include?(full_path)
+          ENV["LDFLAGS"] = "-L#{full_path} #{old_value}".strip
+        end
+      end
+
+      # if we're in an extconf (mkmf.rb sets $LDFLAGS), append the library path. this works around
+      # an issue with fedora's pkgconf as detailed in:
+      #
+      #   https://github.com/flavorjones/mini_portile/issues/118
+      #
+      flag = "-L#{lib_path}"
+      if $LDFLAGS && !$LDFLAGS.split.include?(flag)
+        $LDFLAGS << " #{flag}"
       end
     end
   end