serious trouble on sparc-sun-solaris8

[Benjamin Kunz]

hi,

i guess im fooling myself on this, because i have built many a
./configure-ed program on sol8 before, but i am stuck with a wierd
problem atm:
after making and installing gcc, all FSF configure scripts detect that i
am cross-compiling, making some "test"s fail and exit with an error code
(cannot test for thisandthat while cross-compiling), and generally make
the configure script fail. even reconfiguring gcc fails. (wanted to
compile it with itself)
i would like to know how the check for cross-compilation is done, so
that i can see what causes these problems that seem to be specific to my
configuration.
if the answer is rtfm, please point me to the appropriate source.
thanks. 
i have tried setting -host and -target explictly and also touched the
config.cache to fool it - no change..
maybe i have to build and install some libraries first?

thank you for your help,
        ben