works, but for example C<bin:perl -v> doesn't. The exact reason isn't
known but the current suspect is the F<ixemul> library.
+=head2 Apache 1.3 Doesn't Build With -D_GNU_SOURCE
+
+In Linux, building Apache 1.3 with mod_perl 1.3 and B<threaded> Perl
+5.8.0 does not work because starting from 5.8.0 a threaded Perl uses
+the -D_GNU_SOURCE flag. Apache 1.3 doesn't like that flag and the
+compilation dies in function prototype conflicts. This may or
+not get fixed in later releases of Apache 1.3 (fixing the problem
+in Perl is less likely since Perl now needs the -D_GNU_SOURCE>).
+The workaround is to use a non-threaded Perl or Apache 2.0.
+
=head2 lib/ftmp-security tests warn 'system possibly insecure'
Don't panic. Read INSTALL 'make test' section instead.