On 07/06/2012 12:08, Simon Marlow wrote:
I don't completely understand what is going wrong here, but it looks like an interaction between the RTS's use of a timer signal and the libsane library. You can make it work by turning off GHC's timer with +RTS -V0. [..] The signal has always been SIGVTALRM, as far as I can tell. Which is confusing - if the signal had changed, I could understand that being the cause of the difference in behaviour. Perhaps it is just that system calls are being interrupted by the signal more often than they were before, and libsane does not properly handle EINTR. I looked at the strace output and can't see any use of a signal by libsane.
I see, thanks. I'll do some digging into libsane and see if I can work out more details. Cheers, Ganesh