[GHC] #1620: Bug in debugger 6.7.20070817

[GHC]

#1620: Bug in debugger 6.7.20070817
-------------------------------------+------------------------------------
        Reporter:  guest             |            Owner:
            Type:  bug               |           Status:  closed
        Priority:  normal            |        Milestone:
       Component:  GHCi              |          Version:  6.7
      Resolution:  fixed             |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Changes (by pupfish):

 * cc: hvr (added)
 * failure:   => None/Unknown


Comment:

 I get the same error in 7.8.2 (using ghc-7.8.2-i386-unknown-linux-
 deb7.tar.xz from [http://www.haskell.org/ghc/download_ghc_7_8_2]):

 {{{
 GHCi, version 7.8.2: http://www.haskell.org/ghc/  :? for help
 Loading package ghc-prim ... linking ... done.
 Loading package integer-gmp ... linking ... done.
 Loading package base ... linking ... done.
 Prelude> :cd ticket-1620/
 Prelude> :l qsort.hs
 [1 of 1] Compiling Main             ( qsort.hs, interpreted )
 Ok, modules loaded: Main.
 *Main> :break 2
 Breakpoint 0 activated at qsort.hs:2:16-47
 *Main> :cd ..
 Warning: changing directory causes all loaded modules to be unloaded,
 because the search path has changed.
 Prelude> :cd ticket-1620/
 Prelude> :l qsort.hs
 Failed to load interface for `Main'
 Use -v to see a list of the files searched for.
 Prelude> :l qsort.hs
 *** Exception: ModBreaks.modBreaks_array not initialised
 Prelude>
 }}}

 Contents of qsort.hs (from chapter
 [http://www.haskell.org/ghc/docs/latest/html/users_guide/ghci-
 debugger.html 2.5. The GHCi Debugger] in the GHC user's guide):

 {{{
 qsort [] = []
 qsort (a:as) = qsort left ++ [a] ++ qsort right
   where (left,right) = (filter (<=a) as, filter (>a) as)

 main = print (qsort [8, 4, 0, 3, 1, 23, 11, 18])
 }}}

 I can't seem to load any other files (even in a different directory) when
 this error occurs. I have to restart GHCi in order for it to work
 correctly again. I usually trigger this error by typing ":c" and
 accidentally hitting enter instead of typing ":co" (":continue").

 I'm not sure if it's related to #1650, which was fixed by commit
 [https://github.com/ghc/ghc/commit/e2782137c799a08711cac0844418cc0345a7ceb5
 e2782137c7].

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/1620#comment:4>
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