Hi, Is it possible to persuade ghc/RTS to provide a stack trace (or something similar) when an error occurs? I have some code that is generating a runtime error (appears to be due to division by almost-zero, provoking very large numbers and then a NaN in a case statement when coerced to Double) in a function that is used throughout my code - it would be a big help to know which function called the function that is generating the error. Also, less importantly, how do I generate packages? I have a bunch of .o files (modules) all compiled using -package-name and -c, but I can't find the correct ghc flag to link them into a library (.a/Linux). Apologies if both/either of these are covered in the docs - I couldn't find a simple way of getting a stack trace and no info on actually linking to create a package (when I try various "obvious" things I get errors indicating a missing main). Thanks, Andrew PS Away from home, so having to use my work address. Please reply to the list (which I can read on the 'net and will subscribe to when I get home) or, if you want to avoid that, andrew@andrewcooke.free-online.co.uk, which I will read this weekend. Work isn't happy about non-work-related emails to this account. Sorry.