Local files can be used in recipe sources.

file:// can be used as scheme to make it clearer, but URLs without
scheme will be assumed to be local files anyway.

src/recipe.cr

@@ -57,6 +57,8 @@ class Package::Recipe
 	getter sources       = Sources.new
 	getter packages      = Array(Package).new
 
+	property recipe_directory = "."
+
 	@working_uuid        : UUID = UUID.random
 
 	def initialize(@context, @name, @version)
@@ -78,6 +80,8 @@ class Package::Recipe
 		name : String? = nil
 		version : String? = nil
 
+		@recipe_directory = File.dirname filename
+
 		raise "Could not parse `#{filename}`" if specs.nil?
 
 		specs.assignments.each do |key, value|
@@ -209,7 +213,14 @@ class Package::Recipe
 				raise ExtractionError.new self, url unless status.success?
 			else
 				puts ":: Copying '#{url.filename}'"
-				FileUtils.cp "#{@context.sources_directory}/#{url.filename}",
+
+				directory = if url.scheme == "file"
+					@recipe_directory
+				else
+					@context.sources_directory
+				end
+
+				FileUtils.cp "#{directory}/#{url.filename}",
 					url.filename
 			end
 		end