Blasa compilation error

["Michele A. Torzilli" <mtorzill earthlink net>]

I receive the following error when trying to compile Balsa-0.4.6.2:

misc.c:169: 'errno' undeclared (first use this function)
misc.c:169: (Each undeclared identifier is reported only once
misc.c:169: for each function it appears in.)
misc.c:169: 'EAGAIN' undeclared (first use this function)
misc.c:169: 'EINTR' undeclared (first use this function)
make[2]: ***[misc.o] Error 1
make[2]: Leaving directory '/usr/src/GNOME/balsa-0.4.6.2/libbalsa'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory '/usr/src/GNOME/balsa-0.4.6.2'
make: *** [all-recursive-am] Error 2

Could someone provide some suggestions as to how to resolve this.  Thank you.
--
Michele A. Torzilli
mtorzill@earthlink.net

The first step to knowledge 
is to know we are ignorant.
	 Socrates (470-399 B.C.)