diff --git a/src/main.cr b/src/main.cr
index fe55d00..43e1276 100644
--- a/src/main.cr
+++ b/src/main.cr
@@ -5,41 +5,71 @@ require "./recipe.cr"
 extend Package
 
 # FIXME: recipe.clean? context autoclean?
-Context.new().tap do |context|
-	context.packaging_backend = "apk"
+context = Context.new()
+context.packaging_backend = "apk"
 
-	# FIXME: context.new_recipe? context.recipe?
-	Recipe.new(context, "hello", "2.10").tap do |recipe|
-		recipe.sources << "https://ftp.gnu.org/gnu/hello/hello-2.10.tar.gz"
+recipes = [] of Package::Recipe
 
-		# This is a voluntary mix of automatic and manual build
-		# instructions.
-		# Also, installing in /package makes testing with a real-life
-		# package manager trivial and reduces the damage done in case
-		# of… containment failure. ]:->
-		recipe.instructions.configure << "cd hello-#{recipe.version} && ./configure --prefix=/package"
-		#recipe.instructions.build << "cd hello-#{recipe.version} && make"
-		#recipe.instructions.install << "cd hello-#{recipe.version} && make DESTDIR='${PKG}' install"
+# FIXME: context.new_recipe? context.recipe?
+recipes << Recipe.new(context, "hello", "2.10").tap do |recipe|
+	recipe.sources << "https://ftp.gnu.org/gnu/hello/hello-2.10.tar.gz"
 
-		recipe.url = "https://www.gnu.org/software/hello/"
-		recipe.description = "The GNU Hello program produces a familiar, friendly greeting."
-		recipe.dependencies << "gettext"
+	# This is a voluntary mix of automatic and manual build
+	# instructions.
+	# Also, installing in /package makes testing with a real-life
+	# package manager trivial and reduces the damage done in case
+	# of… containment failure. ]:->
+	recipe.instructions.configure << "cd hello-#{recipe.version} && ./configure --prefix=/package"
+	#recipe.instructions.build << "cd hello-#{recipe.version} && make"
+	#recipe.instructions.install << "cd hello-#{recipe.version} && make DESTDIR='${PKG}' install"
 
-		recipe.auto_split
+	recipe.url = "https://www.gnu.org/software/hello/"
+	recipe.description = "The GNU Hello program produces a familiar, friendly greeting."
+	recipe.dependencies << "gettext"
 
-		# Should be automatic now.
-		#recipe.packages << Package::Package.new(recipe).tap do |package|
-		#	package.name = "#{recipe.name}-man"
-		#	package.files = ["/package/share/man"]
-		#end
+	recipe.auto_split
 
-		recipe.download
-		recipe.extract
+	# Should be automatic now.
+	#recipe.packages << Package::Package.new(recipe).tap do |package|
+	#	package.name = "#{recipe.name}-man"
+	#	package.files = ["/package/share/man"]
+	#end
+end
 
-		raise "oh no, build failed" unless recipe.build
-		recipe.package
+if ARGV.size == 0 || ARGV[0]? == "-h"
+	pp recipes.map &.name
+	exit 0
+end
 
-		recipe.clean
+selected_recipes = ARGV.map do |name|
+	recipes.find(&.name.==(name)) || name
+end
+
+if selected_recipes.any? &.is_a?(String)
+	puts "At least one of the requested recipes is not known."
+
+	selected_recipes.select! &.is_a?(String)
+	pp! selected_recipes
+end
+
+# Getting rid of Strings.
+selected_recipes = selected_recipes.compact_map do |recipe|
+	if recipe.is_a? String
+		nil
+	else
+		recipe
 	end
 end
 
+selected_recipes.each do |recipe|
+	pp recipe
+
+	raise "oh no, download failed" unless recipe.download
+	raise "oh no, extraction failed" unless recipe.extract
+
+	raise "oh no, build failed" unless recipe.build
+	raise "oh no, packaging failed" unless recipe.package
+
+	recipe.clean
+end
+
diff --git a/src/recipe.cr b/src/recipe.cr
index 3359b49..6768c91 100644
--- a/src/recipe.cr
+++ b/src/recipe.cr
@@ -75,22 +75,28 @@ class Package::Recipe
 		@dirname || "#{name}-#{version}"
 	end
 
-	def download
-		sources.map do |url|
-			unless File.exists? url.basename
-				@context.run @context.sources_directory, "wget", [ url.to_s, "-O", url.basename ]
+	def download : Bool
+		sources
+			.compact_map do |url|
+				unless File.exists? url.basename
+					@context.run @context.sources_directory, "wget", [ url.to_s, "-O", url.basename ]
+				end
 			end
-		end
+			.map(&.success?)
+			.reduce(true) { |a, b| a && b }
 	end
 
-	def extract
+	def extract : Bool
 		Dir.mkdir_p building_directory
 
-		sources.map do |url|
-			basename = url.basename
+		sources
+			.map do |url|
+				basename = url.basename
 
-			@context.run building_directory, "tar", [ "xvf", @context.sources_directory + "/" + url.basename ]
-		end
+				@context.run building_directory, "tar", [ "xvf", @context.sources_directory + "/" + url.basename ]
+			end
+			.map(&.success?)
+			.reduce true { |a, b| a && b }
 	end
 
 	# TODO:
@@ -100,7 +106,7 @@ class Package::Recipe
 	#   - Be careful about return values, flee from everything if something
 	#     goes somehow wrong.
 	#   - Make things thread-safe. (those ENV[]= calls are definitely not)
-	def build
+	def build : Bool
 		success = true
 
 		Dir.mkdir_p fake_root_directory
@@ -165,15 +171,18 @@ class Package::Recipe
 	# TODO:
 	#  - Errors management. Stop at first failure?
 	#  - Splits. This should be done between #build and #package.
-	def package
-		# FIXME: if package.automatic and no file, do not build.
-		@packages.find do |package|
-			if package.automatic && ! File.exists? package.fake_root_directory
-				next
-			end
+	def package : Bool
+		# This tries to build them all and stops at the first failure
+		# (failures are currently reported by Context#package)
+		@packages
+			.find do |package|
+				if package.automatic && ! File.exists? package.fake_root_directory
+					next
+				end
 
-			! @context.package package
-		end
+				! @context.package package
+			end
+			.== nil
 	end
 
 	def clean