Thanks for your replies Pavel and Uwe. Ok, it turns out here is my problem: I was using "dbg=all", but this trace level doesn't exist. The one I was after was "any"! I realise others may be more appropriate, but it doesn't take that long on my computer to start with "any" and if you can nail down roughly when the problem happens it doesn't hurt too much to have the extra messages.
> > > By the way, why _is_ there still a LyxLauncher.exe? I thought that > > lyx.exe >was > > being compiled as a native GUI application (annoying for this situation, but > > useful in general)? Is it because I've used the alternative installer? > > Having the possibility to see a debug window is useful, especially for a > test >release like a beta. I try to compile the final LyX 2.0 as native GUI >application. > It's a pity we can't do both/ choose at run time. I'm glad we have Pavel's suggested method works for most cases (I can't believe I missed that!), although obviously it's no good for SIGSEGV. Perhaps if it had the option to write to a file, it would do. Jim
