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

[GHC]

#15721: Command `:show bindings` throws exception for bindings without `let`
-------------------------------------+-------------------------------------
           Reporter:  sighingnow     |             Owner:  (none)
               Type:  bug            |            Status:  new
           Priority:  high           |         Milestone:
          Component:  GHCi           |           Version:  8.6.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  GHCi crash
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 The command `:show bindings` works for `let a = 1`:

 {{{#!hs
 Prelude> let a = 1
 Prelude> :show bindings
 a :: Num p => p = _
 }}}

 But not for `a = 1`:

 {{{#!hs
 Prelude> a = 1
 Prelude> :show bindings
 ghc-stage2.exe: ^^ Could not load 'interactive_Ghci1_zdtrModule2_closure',
 dependency unresolved. See top entry above.

 ghc-stage2.exe: ^^ Could not load 'interactive_Ghci1_zdtrModule4_closure',
 dependency unresolved. See top entry above.

 $trModule :: GHC.Types.Module = _
 $trModule1 :: GHC.Types.TrName = _
 $trModule2 ::
   GHC.Prim.Addr# = *** Exception:
 ByteCodeLink.lookupCE
 During interactive linking, GHCi couldn't find the following symbol:
   interactive_Ghci1_zdtrModule2_closure
 This may be due to you not asking GHCi to load extra object files,
 archives or DLLs needed by your current session.  Restart GHCi, specifying
 the missing library using the -L/path/to/object/dir and -lmissinglibname
 flags, or simply by naming the relevant files on the GHCi command line.
 Alternatively, this link failure might indicate a bug in GHCi.
 If you suspect the latter, please send a bug report to:
   glasgow-haskell-bugs at haskell.org

 $trModule3 :: GHC.Types.TrName = _
 $trModule4 ::
   GHC.Prim.Addr# = *** Exception:
 ByteCodeLink.lookupCE
 During interactive linking, GHCi couldn't find the following symbol:
   interactive_Ghci1_zdtrModule4_closure
 This may be due to you not asking GHCi to load extra object files,
 archives or DLLs needed by your current session.  Restart GHCi, specifying
 the missing library using the -L/path/to/object/dir and -lmissinglibname
 flags, or simply by naming the relevant files on the GHCi command line.
 Alternatively, this link failure might indicate a bug in GHCi.
 If you suspect the latter, please send a bug report to:
   glasgow-haskell-bugs at haskell.org

 a :: Num p => p = _
 a1 :: Integer = _
 }}}

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