[Fluxus] scons library oddness

[gabor papp]

hi Kas,

> video/AR extension. It looked like scons would only clean those parts (or
> perhaps clean at all) once their dependencies were installed.
if the addon requirements are not met the code of that module is not 
compiled, so there's nothing to clean up.

> I find it odd that it would complain about lacking optional dependencies
> when asked to clean, yet at that time not complain about the issue it had
> with libtiff (and likely more non-optional dependencies).
it should not do this. all dependency checks are skipped if the clean 
option is specified. about the libtiff issue, it's always good to check 
your config.log file to see what went wrong. another thing is, if you 
cancel the library detection phase sometimes the data is incorrectly 
cached so it's useful to clean the cache files and directories 
(.sconf_temp and .sconsign.dblite) manually.

best,
gabor