Doesn't build with recent versions of base

[phlummox]

Not sure if you prefer to track issues here or on Bitbucket - I see hackage does list Bitbucket as the official repository, but also that neither repo has been touched in a long while.

At any rate: global-variables isn’t compatible with versions of base since 4.9, due to changes in the API for Data.Typeable.

Three lines need to be patched in order to make it work:

diff --git a/src/Data/Global/Registry.hs b/src/Data/Global/Registry.hs
index e7591ce..d29f2c7 100644
--- a/src/Data/Global/Registry.hs
+++ b/src/Data/Global/Registry.hs
@@ -30,6 +30,7 @@ import Control.Exception       ( evaluate )
 #endif
 import Data.IORef
 import Data.Dynamic
+import Data.Typeable
 import Data.Map as M
 import GHC.Conc                ( pseq )
 import GHC.IO                  ( unsafePerformIO, unsafeDupablePerformIO )
@@ -63,7 +64,7 @@ globalRegistry = m `pseq` unsafePerformIO (newMVar m)

 -- | Exposed for unit testing
 lookupOrInsert
-    :: forall a. forall ref. (Typeable a, Typeable1 ref)
+    :: forall a  ref . (Typeable a, Typeable ref)
     => MVar Registry
     -> (a -> IO (ref a))
     -> String
@@ -79,7 +80,7 @@ lookupOrInsert registry new name val = modifyMVar registry lkup

 #if __GLASGOW_HASKELL__ >= 702
     typVal = typeOf val
-    typRef = typeOf (undefined :: ref ()) -- TypeRep representing the reference, e.g. IORef,
+    typRef = typeOf1 (undefined :: ref ()) -- TypeRep representing the reference, e.g. IORef,
                                           -- MVar

     lkup :: Registry -> IO (Registry, ref a)

I'd be happy to create a pull request if you want.