[Haskell-cafe] :Trace has no history

[Pepe Iborra]

Hi Steve

The debugger only traces calls in interpreted code. Perhaps the call
to myMethod is being made from object code?

Admittedly, the ghci debugger can take some effort to learn to use
properly. Make sure that you give a look to the ghc user guide if you
haven't done so yet.


Best,
pepe

On Tuesday, August 31, 2010, Steve <sseveran at gmail.com> wrote:
> I am trying to debug a problem in GHCI. I invoke my method with trace
> but when it breaks on exception i can't get this history. Output is
> below. Thanks.
>
>
> relude Symbols> :set -fbreak-on-exception
> Prelude Symbols> :trace myMethod
> Loading package HUnit-1.2.2.1 ... linking ... done.
> Loading package syb-0.1.0.2 ... linking ... done.
> Loading package base-3.0.3.2 ... linking ... done.
> Loading package old-locale-1.0.0.2 ... linking ... done.
> Loading package time-1.1.4 ... linking ... done.
> Loading package random-1.0.0.2 ... linking ... done.
> Loading package QuickCheck-1.2.0.0 ... linking ... done.
> Loading package Decimal-0.1.0 ... linking ... done.
> Loading package array-0.3.0.0 ... linking ... done.
> Loading package Diff-0.1.2 ... linking ... done.
> Loading package bytestring-0.9.1.5 ... linking ... done.
> Loading package containers-0.3.0.0 ... linking ... done.
> Loading package mtl-1.1.0.2 ... linking ... done.
> Loading package old-time-1.0.0.3 ... linking ... done.
> Loading package convertible-1.0.9 ... linking ... done.
> Loading package utf8-string-0.3.4 ... linking ... done.
> Loading package HDBC-2.2.6 ... linking ... done.
> Loading package HDBC-mysql-0.6.3 ... linking ... done.
> Loading package parsec-2.1.0.1 ... linking ... done.
> Loading package network-2.2.1.7 ... linking ... done.
> Loading package HTTP-4000.0.9 ... linking ... done.
> Loading package binary-0.5.0.2 ... linking ... done.
> Loading package digest-0.0.0.8 ... linking ... done.
> Loading package filepath-1.1.0.3 ... linking ... done.
> Loading package unix-2.4.0.0 ... linking ... done.
> Loading package directory-1.0.1.0 ... linking ... done.
> Loading package pretty-1.0.1.1 ... linking ... done.
> Loading package zlib-0.5.2.0 ... linking ... done.
> Loading package zip-archive-0.1.1.6 ... linking ... done.
> Loading package Core-0.0.1 ... linking ... done.
> Beginning Update
> Stopped at <exception thrown>
> _exception ::
>  e = GHC.Exception.SomeException (GHC.Exception.D:Exception _
>
> (GHC.Show.D:Show ...) ....)
>                                  (GHC.IO.Exception.IOError Nothing
> GHC.IO.Exception.UserError ....)
> [<exception thrown>] Prelude Symbols> :history
> Empty history. Perhaps you forgot to use :trace?
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-- 
-- José Iborra        http://www.dsic.upv.es/~jiborra
-- UPV Valencia       Telf. (+34) 96 387 00 00 (ext) 83529
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