add unsupportedOS

2 files changed, 3 insertions, 5 deletions

diff --git a/src/Propellor/Property/Apt.hs b/src/Propellor/Property/Apt.hs
index eae56ab5..7301a6ae 100644
--- a/src/Propellor/Property/Apt.hs
+++ b/src/Propellor/Property/Apt.hs
@@ -160,16 +160,14 @@ installed' params ps = robustly $ check (isInstallable ps) go
 
 installedBackport :: [Package] -> Property NoInfo
 installedBackport ps = withOS desc $ \o -> case o of
-	Nothing -> error "cannot install backports; os not declared"
 	(Just (System (Debian suite) _)) -> case backportSuite suite of
-		Nothing -> notsupported o
+		Nothing -> unsupportedOS
 		Just bs -> ensureProperty $
 			runApt (["install", "-t", bs, "-y"] ++ ps)
 				`changesFile` dpkgStatus
-	_ -> notsupported o
+	_ -> unsupportedOS
   where
 	desc = unwords ("apt installed backport":ps)
-	notsupported o = error $ "backports not supported on " ++ show o
 
 -- | Minimal install of package, without recommends.
 installedMin :: [Package] -> Property NoInfo
diff --git a/src/Propellor/Property/OS.hs b/src/Propellor/Property/OS.hs
index 5f1adddb..e5da0921 100644
--- a/src/Propellor/Property/OS.hs
+++ b/src/Propellor/Property/OS.hs
@@ -86,7 +86,7 @@ cleanInstallOnce confirmation = check (not <$> doesFileExist flagfile) $
 	osbootstrapped = withOS (newOSDir ++ " bootstrapped") $ \o -> case o of
 		(Just d@(System (Debian _) _)) -> debootstrap d
 		(Just u@(System (Buntish _) _)) -> debootstrap u
-		_ -> error "os is not declared to be Debian or *buntu"
+		_ -> unsupportedOS
 	
 	debootstrap targetos = ensureProperty $
 		-- Ignore the os setting, and install debootstrap from