darcs setup diff

a.diff

--- old-darcs-2.12/Setup.lhs	2016-08-30 07:33:48.000000000 -0700
+++ new-darcs-2.12/Setup.lhs	2016-08-30 07:33:48.000000000 -0700
@@ -75,6 +75,8 @@
 
 import qualified Control.Exception as Exception
 
+import Text.Show.Pretty
+
 catchAny f h = Exception.catch f (\e -> h (e :: Exception.SomeException))
 
 {- Template Haskell hackery for replHook while we want to support Cabal < 1.18 -}
@@ -146,7 +148,8 @@
           let pkgDescr = localPkgDescr lbi
           let verb = fromFlag (configVerbosity flags)
           checkForeignDeps pkgDescr lbi verb
-          let Just lib = library pkgDescr
+          putStrLn $ ppShow pkgDescr -- XXX
+          let Just lib = library pkgDescr -- XXX pattern match failure
           let bi = libBuildInfo lib
           bi' <- maybeSetLibiconv flags bi lbi
           return lbi {localPkgDescr = pkgDescr {