[GHC] #10375: arm: ghci hits an illegal instruction

[GHC]

#10375: arm: ghci hits an illegal instruction
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        Reporter:  erikd             |                   Owner:
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:  7.10.2
       Component:  GHCi              |                 Version:  7.10.1
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:  arm
 Type of failure:  GHCi crash        |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
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Comment (by erikd):

 This is definitely not statically linked (the `lld` command shows
 dynamically linked Haskell libraries like `haskeline`, `terminfo`,
 `transformers` as well as the usual C library suspects.

 Debugging this in GDB is *really* difficult. Firstly, I can only recreate
 the problem when running with `--interactive`. Secondly, GDB and `ghc-
 stage2 --interactive` both try to take control of the same terminals so I
 have to start the `ghc-stage2 --interactive` process and connect gdb to it
 with `gdb -p $(pidof ghc-stage2)`. The `.gchi` file contains:

 {{{
 putStr "Continue ... "
 _ <- getChar
 putStrLn "ok"
 data X = Y deriving Eq
 Y == Y
 }}}

 The `getChar` is there to pause the `ghc-stage2` process long enough to
 attach GDB. Unfortunately, this means that the number of passes through
 the code I'm trying to debug is not deterministic which makes setting a
 breakpoint rather difficult.

 I am currently playing around with replacing `getChar` with `threadDelay`
 to see if I can make it determinisitc.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10375#comment:17>
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