Add missing special case for GHC.Prim

The special cases for GHC.Prim are a bit fragile.  We were relying on
(a) the base package to be already registered and (b) the base package
not to be hidden.  These used to be true with the old library build
system, but aren't true now.  I'm still not sure why we aren't seeing
failures at the moment, but this patch at least fixes the build with
'setup makefile'.

diff --git a/compiler/main/Finder.lhs b/compiler/main/Finder.lhs
index df1fa3e..56929ce 100644 (file)
--- a/compiler/main/Finder.lhs
+++ b/compiler/main/Finder.lhs
@@ -243,6 +243,14 @@ findHomeModule hsc_env mod_name =
      exts | isOneShot (ghcMode dflags) = hi_exts
           | otherwise                 = source_exts
    in
+
+  -- special case for GHC.Prim; we won't find it in the filesystem.
+  -- This is important only when compiling the base package (where GHC.Prim
+  -- is a home module).
+  if mod == gHC_PRIM 
+        then return (Found (error "GHC.Prim ModLocation") mod)
+        else 
+
    searchPathExts home_path mod exts