Some problem for Makefile of firefox

[K.C.Leung ( 聰 ) <z4423569 gmail com>]

While at the configure time of firefox by using garnome, it complain that 
xft is not found.

I've check the configure file.
And echo $PKG_CONFIG_PATH for debug at the last line of such error.
I shown that the PKG_CONFIG_PATH is difference with my system.

I've unset PKG_CONFIG_PATH and
source /etc/profile again
at the configure file.
Finally, all the configure passed.

Please check that. thanks!