Re: [Haskell-cafe] Best way to find an undefined error?
saynte: Hello all, Does anyone favourite technique to track down an undefined call? I'm 99% sure that my code is not the offender (I've grepped for undefined occurrences and turned them all into error calls). Supposing that this is happening in some other package or library that I'm using, what is the best way to find out where it is? I have profiling enabled on all libraries that I use, so I'm ok there I think. Any magic combination of +RTS .. -RTS? You can use the profiler to get a stack trace, or use the new GHCi debugger to step backwards from the exception to the source. I wrote a bit of a tutorial for this here: http://cgi.cse.unsw.edu.au/~dons/blog/2007/11/14#no-exceptions -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Best way to find an undefined error?
On Thu, Feb 14, 2008 at 2:55 PM, Don Stewart [EMAIL PROTECTED] wrote: You can use the profiler to get a stack trace, or use the new GHCi debugger to step backwards from the exception to the source. I wrote a bit of a tutorial for this here: http://cgi.cse.unsw.edu.au/~dons/blog/2007/11/14#no-exceptions Section 6.3 of http://haskell.org/haskellwiki/Debugging also is relevant for using ghcu to step backward ... perhaps the section label is misleading, though. Feel free to modify as needed if you find the ghci stepper lets you find the problem -- Denis ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Best way to find an undefined error?
On Thu, Feb 14, 2008 at 3:02 PM, Denis Bueno [EMAIL PROTECTED] wrote: On Thu, Feb 14, 2008 at 2:55 PM, Don Stewart [EMAIL PROTECTED] wrote: You can use the profiler to get a stack trace, or use the new GHCi debugger to step backwards from the exception to the source. I wrote a bit of a tutorial for this here: http://cgi.cse.unsw.edu.au/~dons/blog/2007/11/14#no-exceptions Section 6.3 of http://haskell.org/haskellwiki/Debugging also is relevant for using ghcu to step backward ... perhaps the section label is misleading, though. Feel free to modify as needed if you find the ghci stepper lets you find the problem Well, when using +RTS -xc, I get: GHC.Err.CAFGHC.Err.CAFPrelude.undefined I'm not really sure what to do with this, not really the stacktrace I was hoping for. The ghci debugger I found was really quite nice, up until it his some portion of code that it isn't interpreting. By not interpreting i mean things that have been already been compiled and it's just calling (even if it has been compiled with profiling). I have a feeling that my problem is somewhere in something that has already been compiled. Knowing that, should +RTS -xc be giving me more information? Is there a way for it to do so? Regards, Scott ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Best way to find an undefined error?
saynte: On Thu, Feb 14, 2008 at 3:02 PM, Denis Bueno [EMAIL PROTECTED] wrote: On Thu, Feb 14, 2008 at 2:55 PM, Don Stewart [EMAIL PROTECTED] wrote: You can use the profiler to get a stack trace, or use the new GHCi debugger to step backwards from the exception to the source. I wrote a bit of a tutorial for this here: http://cgi.cse.unsw.edu.au/~dons/blog/2007/11/14#no-exceptions Section 6.3 of http://haskell.org/haskellwiki/Debugging also is relevant for using ghcu to step backward ... perhaps the section label is misleading, though. Feel free to modify as needed if you find the ghci stepper lets you find the problem Well, when using +RTS -xc, I get: GHC.Err.CAFGHC.Err.CAFPrelude.undefined I'm not really sure what to do with this, not really the stacktrace I was hoping for. The ghci debugger I found was really quite nice, up until it his some portion of code that it isn't interpreting. By not interpreting i mean things that have been already been compiled and it's just calling (even if it has been compiled with profiling). I have a feeling that my problem is somewhere in something that has already been compiled. Is it possible to just load all the code interpreted? Or is the problem in a dependent library? If you profile and let the program terminate, there should be a stack trace in the .prof as well. -- Don ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Best way to find an undefined error?
On Thu, Feb 14, 2008 at 4:43 PM, Don Stewart [EMAIL PROTECTED] wrote: saynte: On Thu, Feb 14, 2008 at 3:02 PM, Denis Bueno [EMAIL PROTECTED] wrote: On Thu, Feb 14, 2008 at 2:55 PM, Don Stewart [EMAIL PROTECTED] wrote: You can use the profiler to get a stack trace, or use the new GHCi debugger to step backwards from the exception to the source. I wrote a bit of a tutorial for this here: http://cgi.cse.unsw.edu.au/~dons/blog/2007/11/14#no-exceptions Section 6.3 of http://haskell.org/haskellwiki/Debugging also is relevant for using ghcu to step backward ... perhaps the section label is misleading, though. Feel free to modify as needed if you find the ghci stepper lets you find the problem Well, when using +RTS -xc, I get: GHC.Err.CAFGHC.Err.CAFPrelude.undefined I'm not really sure what to do with this, not really the stacktrace I was hoping for. The ghci debugger I found was really quite nice, up until it his some portion of code that it isn't interpreting. By not interpreting i mean things that have been already been compiled and it's just calling (even if it has been compiled with profiling). I have a feeling that my problem is somewhere in something that has already been compiled. Is it possible to just load all the code interpreted? Or is the problem in a dependent library? If you profile and let the program terminate, there should be a stack trace in the .prof as well. -- Don Well, I can load a bunch of it interpreted. I've already done this as far as I think I can. The only pieces laying outside the interpreter are the GHC libraries and Gtk2Hs. The really funny thing, is that (essentially) I believe the error results from a call to fromDynamic out of Data.Dynamic. This sort of leads me to believe that someone's Typeable instance is being funny. Again though, all the Typeable's in the immediate area of my code seem to be fine. (the .prof didn't seem to reveal anything yet... I'll look it over a little more closely though) Regards, Scott ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Best way to find an undefined error?
On Thu, Feb 14, 2008 at 5:12 PM, Scott West [EMAIL PROTECTED] wrote: On Thu, Feb 14, 2008 at 4:43 PM, Don Stewart [EMAIL PROTECTED] wrote: saynte: On Thu, Feb 14, 2008 at 3:02 PM, Denis Bueno [EMAIL PROTECTED] wrote: On Thu, Feb 14, 2008 at 2:55 PM, Don Stewart [EMAIL PROTECTED] wrote: You can use the profiler to get a stack trace, or use the new GHCi debugger to step backwards from the exception to the source. I wrote a bit of a tutorial for this here: http://cgi.cse.unsw.edu.au/~dons/blog/2007/11/14#no-exceptions Section 6.3 of http://haskell.org/haskellwiki/Debugging also is relevant for using ghcu to step backward ... perhaps the section label is misleading, though. Feel free to modify as needed if you find the ghci stepper lets you find the problem Well, when using +RTS -xc, I get: GHC.Err.CAFGHC.Err.CAFPrelude.undefined I'm not really sure what to do with this, not really the stacktrace I was hoping for. The ghci debugger I found was really quite nice, up until it his some portion of code that it isn't interpreting. By not interpreting i mean things that have been already been compiled and it's just calling (even if it has been compiled with profiling). I have a feeling that my problem is somewhere in something that has already been compiled. Is it possible to just load all the code interpreted? Or is the problem in a dependent library? If you profile and let the program terminate, there should be a stack trace in the .prof as well. -- Don Well, I can load a bunch of it interpreted. I've already done this as far as I think I can. The only pieces laying outside the interpreter are the GHC libraries and Gtk2Hs. The really funny thing, is that (essentially) I believe the error results from a call to fromDynamic out of Data.Dynamic. This sort of leads me to believe that someone's Typeable instance is being funny. Again though, all the Typeable's in the immediate area of my code seem to be fine. (the .prof didn't seem to reveal anything yet... I'll look it over a little more closely though) Regards, Scott I did finally find the error (in one of the pieces of code not written by myself). A few instances of Typeable were trying to pattern match their arguments. *bomb* In either case, it was an interesting experience! Thanks for the help all! Regards, Scott ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
