[GHC] #9903: GHCi produces a cryptic message when using HPC

[GHC]

#9903: GHCi produces a cryptic message when using HPC
-------------------------------------+-------------------------------------
              Reporter:              |            Owner:
  facundo.dominguez                  |           Status:  new
                  Type:  bug         |        Milestone:
              Priority:  normal      |          Version:  7.9
             Component:  GHCi        |         Keywords:  hpc
            Resolution:              |     Architecture:  Unknown/Multiple
      Operating System:              |       Difficulty:  Unknown
  Unknown/Multiple                   |       Blocked By:
       Type of failure:  GHCi crash  |  Related Tickets:  #9878, #9762 ?
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
-------------------------------------+-------------------------------------
Description changed by facundo.dominguez:

Old description:

> The following test produces an impolite response from GHCi
>
> {{{
> $ cat t.hs
> g :: Int
> g = 1 + 1
> $ ghc-stage2 --interactive t.hs -fhpc
> GHCi, version 7.9.20141217: http://www.haskell.org/ghc/  :? for help
> [1 of 1] Compiling Main             ( t.hs, interpreted )
> Ok, modules loaded: Main.
> *Main> g
> ghc-stage2: panic! (the 'impossible' happened)
>   (GHC version 7.9.20141217 for x86_64-unknown-linux):
>         Loading temp shared object failed: /tmp/ghc25774_0/ghc25774_5.so:
> undefined symbol: _hpc_tickboxes_Main_hpc
>
> Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
> }}}
> It has been noted elsewhere (#9878) that these kinds of messages are
> better avoided.

New description:

 The following test produces an impolite response from GHCi

 {{{
 $ cat t.hs
 g :: Int
 g = 1 + 1
 $ ghc-stage2 --interactive t.hs -fhpc
 GHCi, version 7.9.20141217: http://www.haskell.org/ghc/  :? for help
 [1 of 1] Compiling Main             ( t.hs, interpreted )
 Ok, modules loaded: Main.
 *Main> g
 ghc-stage2: panic! (the 'impossible' happened)
   (GHC version 7.9.20141217 for x86_64-unknown-linux):
         Loading temp shared object failed: /tmp/ghc25774_0/ghc25774_5.so:
 undefined symbol: _hpc_tickboxes_Main_hpc

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
 }}}
 Discovered while investigating #9878.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9903#comment:1>
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