[GHC] #12494: Implementation of setenv in base incorrectly claims empty environment variable not supported on Windows

[GHC]

#12494: Implementation of setenv in base incorrectly claims empty environment
variable not supported on Windows
-------------------------------------+-------------------------------------
        Reporter:  ezyang            |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  libraries/base    |              Version:  8.0.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by hvr):

 Btw, if we go for the first option, i.e. just change semantics of the
 existing `setEnv` operation (in which case I'd argue not to use any
 warnings, as we don't have any facility to properly acknowledge specific
 warnings yet), then we need to make sure that the hackage:setenv package
 gets retrofitted with an upper bound on `base`, since `setenv` re-exports
 `setEnv` from `base`...

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12494#comment:6>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler