[Clfs-support] clfs-multilib-x86 chroot and PKG_CONFIG_PATH reference to /tools/lib question

[lux-integ]

Greetings

I am working through current clfs(git)  mulilib (x86 book ) and I am puzzled 
that in the chroot location there are references to 
PKG_CONFIG_PATH=/tools/lib64/pkgconfig

at 10.77
http://clfs.org/view/git/x86_64/final-system/kbd.html
( for kbd-2.0.2)
and 10.79 here
http://clfs.org/view/git/x86_64/final-system/libpipeline-64bit.html
for libpipeline-1.40=.0  (64-bit )


I am curious as to why potential linking to libraries in the toolchain  
would not be erroneous.

comments welcome

sincerely
lxInteg