[ardour-users] PKG_CONFIG_PATH?

[dragon fly]

ok guys,
the only what i can find about pkg_config on my mashine is in 
/usr/lib/pkgconfig/examplefile.pc!
building ardour, scons is missing the .pc files of some libraries, by ex: 
sndfile.pc
this file i cannot find anywhere, but sndfile is installed correctly!
so i understand, that i have to find this .pc file and export that into 
PKG_CONFIG_PATH
when i try the last suggestion with ....=..., i dont get error message, but 
nothing happens,
and scons still gives the same error
thanx a lot,
doc