[GHC] #14299: GHCi for GHC 8.2.1 crashed with simple function?

[GHC]

#14299: GHCi for GHC 8.2.1 crashed with simple function?
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        Reporter:  mathiassm   |                Owner:  (none)
            Type:  bug         |               Status:  new
        Priority:  normal      |            Milestone:
       Component:  GHCi        |              Version:  8.2.1
      Resolution:              |             Keywords:
Operating System:  MacOS X     |         Architecture:  x86_64 (amd64)
 Type of failure:  GHCi crash  |            Test Case:
      Blocked By:              |             Blocking:
 Related Tickets:              |  Differential Rev(s):
       Wiki Page:              |
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Description changed by mathiassm:

Old description:

> I'm a newbie here, but I'm following your instructions!
>
> I started GHCi, defined a simple factorial function and then called it
> and... it crashed.
>
> {{{#!hs
> let f 0 = 0
> f n = n * f (n-1)
> f 0
> }}}
>
> That is what I introduced in the console... After that computer hanged
> and gave me the following error:
>
> {{{
> ghc: panic! (the 'impossible' happened)
>   (GHC version 8.2.1 for x86_64-apple-darwin):
>         thread blocked indefinitely in an MVar operation
>
> Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
> }}}

New description:

 I'm a newbie here, but I'm following your instructions!

 I started GHCi, defined a simple factorial function and then called it
 and... it crashed.

 {{{#!hs
 let f 0 = 0
 f n = n * f (n-1)
 f 0
 }}}

 That is what I introduced in the console... After that computer hanged and
 gave me the following error:

 {{{
 ghc: panic! (the 'impossible' happened)
   (GHC version 8.2.1 for x86_64-apple-darwin):
         thread blocked indefinitely in an MVar operation

 Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug
 }}}


 EDIT: This was done on a macOS 10.12.6 system with the Haskell Platform
 installed via Homebrew, with no further "customization".

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14299#comment:1>
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