Propellor now builds itself without needing the Makefile.

Makefile

@@ -9,18 +9,10 @@ run: deps build
 
 dev: build tags
 
-build: dist/setup-config
-	@if ! $(CABAL) build; then $(CABAL) configure; $(CABAL) build; fi
-	@ln -sf dist/build/propellor-config/propellor-config propellor
-
 deps:
 	@if [ $$(whoami) = root ]; then apt-get --no-upgrade --no-install-recommends -y install $(DEBDEPS) || (apt-get update && apt-get --no-upgrade --no-install-recommends -y install $(DEBDEPS)); fi || true
 	@if [ $$(whoami) = root ]; then apt-get --no-upgrade --no-install-recommends -y install libghc-async-dev || (cabal update; cabal install async); fi || true
 
-dist/setup-config: propellor.cabal
-	@if [ "$(CABAL)" = ./Setup ]; then ghc --make Setup; fi
-	@$(CABAL) configure
-
 install: propellor.1
 	install -d $(DESTDIR)/usr/bin $(DESTDIR)/usr/src/propellor
 	install -s dist/build/propellor/propellor $(DESTDIR)/usr/bin/propellor
@@ -56,3 +48,14 @@ hackage:
 	@cabal upload dist/*.tar.gz
 
 .PHONY: tags
+
+# The rules below are only used when bootstrapping new propellor
+# installations; propellor contains equivilant haksell code.
+
+build: dist/setup-config
+	@if ! $(CABAL) build; then $(CABAL) configure; $(CABAL) build; fi
+	@ln -sf dist/build/propellor-config/propellor-config propellor
+
+dist/setup-config: propellor.cabal
+	@if [ "$(CABAL)" = ./Setup ]; then ghc --make Setup; fi
+	@$(CABAL) configure

debian/changelog

@@ -4,6 +4,7 @@ propellor (2.2.0) UNRELEASED; urgency=medium
     improve process name visible in ps.
   * Add shebang to cron.daily etc files. 
   * Some changes to tor configuration, minor API change.
+  * Propellor now builds itself without needing the Makefile.
 
  -- Joey Hess <id@joeyh.name>  Mon, 16 Feb 2015 19:00:48 -0400
 

propellor.cabal

@@ -128,6 +128,7 @@ Library
     Propellor.Types.Result
     Propellor.Types.CmdLine
   Other-Modules:
+    Propellor.Bootstrap
     Propellor.Git
     Propellor.Gpg
     Propellor.Spin

src/Propellor/Bootstrap.hs

@@ -0,0 +1,42 @@
+module Propellor.Bootstrap (
+	buildPropellor
+) where
+
+import Propellor
+import Utility.SafeCommand
+
+import System.Posix.Files
+
+buildPropellor :: IO ()
+buildPropellor = unlessM (actionMessage "Propellor build" build) $
+	errorMessage "Propellor build failed!"
+
+-- Build propellor using cabal, and symlink propellor to where cabal
+-- leaves the built binary.
+--
+-- For speed, only runs cabal configure when it's not been run before.
+-- If the build fails cabal may need to have configure re-run.
+build :: IO Bool
+build = catchBoolIO $ do
+	make "dist/setup-config" ["propellor.cabal"] $
+		cabal ["configure"]
+	unlessM (cabal ["build"]) $ do
+		void $ cabal ["configure"]
+		unlessM (cabal ["build"]) $
+			error "cabal build failed"
+	nukeFile "propellor"
+	createSymbolicLink "dist/build/propellor-config/propellor-config" "propellor"
+	return True
+
+make :: FilePath -> [FilePath] -> IO Bool -> IO ()
+make dest srcs builder = do
+	dt <- getmtime dest
+	st <- mapM getmtime srcs
+	when (dt == Nothing || any (> dt) st) $
+		unlessM builder $
+			error $ "failed to make " ++ dest
+  where
+	getmtime = catchMaybeIO . getModificationTime
+
+cabal :: [String] -> IO Bool
+cabal = boolSystem "cabal" . map Param

src/Propellor/CmdLine.hs

@@ -12,6 +12,7 @@ import qualified Network.BSD
 import Propellor
 import Propellor.Gpg
 import Propellor.Git
+import Propellor.Bootstrap
 import Propellor.Spin
 import Propellor.Types.CmdLine
 import qualified Propellor.Property.Docker as Docker
@@ -31,6 +32,7 @@ usage h = hPutStrLn h $ unlines
 	, "  propellor --edit field context"
 	, "  propellor --list-fields"
 	, "  propellor --merge"
+	, "  propellor --build"
 	]
 
 usageError :: [String] -> IO a
@@ -128,19 +130,16 @@ unknownhost h hosts = errorMessage $ unlines
 	]
 
 buildFirst :: CmdLine -> IO () -> IO ()
-buildFirst cmdline next = ifM (doesFileExist "Makefile")
-	( do
-		oldtime <- getmtime
-		ifM (actionMessage "Propellor build" $ boolSystem "make" [Param "build"])
-			( do
-				newtime <- getmtime
-				if newtime == oldtime
-					then next
-					else void $ boolSystem "./propellor" [Param "--continue", Param (show cmdline)]
-			, errorMessage "Propellor build failed!" 
-			)
-	, next
-	)
+buildFirst cmdline next = do
+	oldtime <- getmtime
+	buildPropellor
+	newtime <- getmtime
+	if newtime == oldtime
+		then next
+		else void $ boolSystem "./propellor"
+			[ Param "--continue"
+			, Param (show cmdline)
+			]
   where
 	getmtime = catchMaybeIO $ getModificationTime "propellor"
 
@@ -155,10 +154,12 @@ updateFirst cmdline next = ifM hasOrigin (updateFirst' cmdline next, next)
 
 updateFirst' :: CmdLine -> IO () -> IO ()
 updateFirst' cmdline next = ifM fetchOrigin
-	( ifM (actionMessage "Propellor build" $ boolSystem "make" [Param "build"])
-		( void $ boolSystem "./propellor" [Param "--continue", Param (show cmdline)]
-			, errorMessage "Propellor build failed!" 
-		)
+	( do
+		buildPropellor
+		void $ boolSystem "./propellor"
+			[ Param "--continue"
+			, Param (show cmdline)
+			]
 	, next
 	)
 

src/wrapper.hs

@@ -15,6 +15,7 @@
 module Main where
 
 import Propellor.Message
+import Propellor.Bootstrap
 import Utility.UserInfo
 import Utility.Monad
 import Utility.Process
@@ -91,13 +92,10 @@ wrapper args propellordir propellorbin = do
 					warnoutofdate propellordir True
 	buildruncfg = do
 		changeWorkingDirectory propellordir
-		ifM (boolSystem "make" [Param "build"])
-			( do
-				putStrLn ""
-				putStrLn ""
-				chain
-			, error "Propellor build failed."
-			)
+		buildPropellor
+		putStrLn ""
+		putStrLn ""
+		chain
 	chain = do
 		(_, _, _, pid) <- createProcess (proc propellorbin args) 
 		exitWith =<< waitForProcess pid