[GHC] #12549: Panic on ":t datatypeName"

[GHC]

#12549: Panic on ":t datatypeName"
---------------------------------+--------------------------------------
        Reporter:  johnleo       |                Owner:  johnleo
            Type:  bug           |               Status:  new
        Priority:  normal        |            Milestone:
       Component:  Compiler      |              Version:  8.1
      Resolution:                |             Keywords:
Operating System:  MacOS X       |         Architecture:  x86_64 (amd64)
 Type of failure:  None/Unknown  |            Test Case:
      Blocked By:                |             Blocking:
 Related Tickets:                |  Differential Rev(s):
       Wiki Page:                |
---------------------------------+--------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"2350906bfb496758d81caf3b66b232e1950285e9/ghc" 2350906/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="2350906bfb496758d81caf3b66b232e1950285e9"
 Maintain in-scope set in deeply_instantiate (fixes #12549).

 Maintain in-scope set in deeply_instantiate (Fixes T12549).

 lint fixes

 Test Plan: validate

 Reviewers: simonpj, austin, goldfire, bgamari

 Reviewed By: simonpj, bgamari

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D2757

 GHC Trac Issues: #12549
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12549#comment:27>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler