David Roundy writes:

The problem is trying to figure out where I'm doing this. Unfortunately, I have only been able to see this error on a rather large test repository, where it takes seven minutes for the test to show up.

Hah! *My* program can take hours before it crashes.

Any suggestions how I might most easily track this bug down?

Did you try compiling with -prof -auto-all, and running with +RTS -xc? -kzm -- If I haven't seen further, it is by standing in the footprints of giants

On Wed, 28 May 2003 09:36:31 -0400 David Roundy wrote:

In some code which uses UArrays, I'm getting the following error:

Fail: Ix{Int}.index: Index (3723) out of range ((0,3722))

Presumably this means I'm trying to access one beyond the end of an array. The problem is trying to figure out where I'm doing this. Unfortunately, I have only been able to see this error on a rather large test repository, where it takes seven minutes for the test to show up.

Any suggestions how I might most easily track this bug down? -- David Roundy http://www.abridgegame.org

1) (If you are using GHC) compile for profiling and use the -xc runtime option. This causes GHC to dump a "stack" dump when an exception is thrown. 2) See the various debuggers that are out there. I haven't used Hat (is a pain to compile on Win2k with 64MB) but it seems like your best bet. Buddha may work but it would require you to mark a lot of code trusted likely to avoid running out of memory or taking all day. 3) Classic debugging: throw traces (or use HOOD, HOOD is Debug.Trace on massive steroids) in suspected parts of your code and see what looks wrong. I think HOOD has some kind of support for exceptions so it may dump out some very helpful information. 4) Classic debugging part two: chop out code, make tests, you certainly know the drill.