On 1 Sep 2014, at 13:41, Graeme Gill wrote: > Richard Kirk wrote: > >> Thanks for looking at this, particularly as I suspect this is an OS problem. >> >> I am running sudo /usr/local/bin/spotread -e -v -D9. I connect to the >> instrument, do a >> self-calibration, and then quit. >> >> I have attached a zip of the co bined stderr and stdout in spotread_log.zip, >> which will >> unpack to spotread.log ( 370394 bytes ). > > Hi, > I don't really have much of an ideal as to what will cause > poll() to fail after working successfully, apart from something > like the device being closed on it. I guess there's a possibility > of something like that being an explanation, some daemon or server > clobbering the USB port which mightn't be able to happen when > spotread has it open as root. > > Is there something like an old version of mtp-probe / libmtp running ? > It was known for clobering color instruments. > (look in the udev configuration). Hi, Graham. I could find no sign of it in the usual directories. Having a search on the web, this seems to often be connected with using Spyders, and we haven't got one. I also have the same thing happening on two separate machines - it is just possible that I may install some test software that stuck it somewhere unusual on one of them, but I doubt if it happens on both. So, I am about as sure as I can be that that is not it. I am sure the real clue lies in the fact I can run it under 'su root' but not under 'su'. I shall work on that. I have tried all the different 'sudo' options to try and get the environments and shells to match. Thanks. Richard Kirk --- FilmLight Ltd, Artists House, 14-15 Manette Street, London W1D 4AP Tel: +44 (0)20 7292 0400 Fax: +44 (0)20 7292 0401