[GHC] #15721: Command `:show bindings` throws exception for bindings without `let`

[GHC]

#15721: Command `:show bindings` throws exception for bindings without `let`
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        Reporter:  sighingnow        |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:
       Component:  GHCi              |              Version:  8.6.1
      Resolution:                    |             Keywords:  newcomer
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  GHCi crash        |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Changes (by mpickering):

 * keywords:   => newcomer


Comment:

 I can't reproduce this on linux so it seems like a windows problem.

 Two other strange things about `x = a`

 {{{
 let x = 'a'
 x = 'a'
 }}}

 doesn't warn about name shadowing.

 If you inspect the heap representation of the two versions of `x` they are
 also different. The latter is a thunk whilst the former is just the
 character.

 Making `x = a` behave exactly like `let x = a` will probably fix this
 ticket the above two problems as well.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15721#comment:1>
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