[Haskell-cafe] Where is the documentation on exception types kept?

Hello, I am trying to catch an "thread blocked on MVar indefinitely exception."  Of course I can use ::SomeException as explained in http://hackage.haskell.org/ packages/archive/base/latest/doc/html/Control-Exception.html#g:3 but there is no explanation as to how to find the more case specific exceptions.  http://hackage.haskell.org/packages/archive/base/latest/doc/html/Control- Concurrent-MVar.html#t:MVar does not discuss exceptions at all!  Indeed, I don't know of any haddock pages that include descriptions of exception types :( :O Thanks, Timothy