Error "making" php with informix

Hi, I'm trying to install php-4.0.6 in my SCO Unix box but when I run the make command I get the next error: /bin/sh ../libtool --silent --mode=link gcc -g -O2 -o libZend.la -lifsql -lif asf -lifgen -lifos -lifgls -lnsl_s -lcrypt_i -lgen -lsocket -lnsl -lsuds -ltinfo -lprot -lx -ltinfo -lc -lphpifx -lifglx -lcrypt -lm -lsocket -lifsql -lifasf -l ifgen -lifos -lifgls -lnsl_s -lcrypt_i /usr/lib/libgen.a -lsocket -lnsl -lm -lsu ds -ltinfo -lprot -lx -ltinfo -lm -lc /usr/informix/lib/esql/checkapi.o -lsocket zend_language_parser.lo zend_ini_parser.lo zend_alloc.lo zend_compile.lo zend_ constants.lo zend_dynamic_array.lo zend_execute.lo zend_execute_API.lo zend_high light.lo zend_llist.lo zend_opcode.lo zend_operators.lo zend_ptr_stack.lo zend_s tack.lo zend_variables.lo zend.lo zend_API.lo zend_extensions.lo zend_hash.lo ze nd_list.lo zend_indent.lo zend_builtin_functions.lo zend_sprintf.lo zend_ini.lo libZend_c.la libtool: link: cannot build libtool library `libZend.la' from non-libtool object s: /usr/lib/libgen.a /usr/informix/lib/esql/checkapi.o make[1]: *** [libZend.la] Error 1 make[1]: Leaving directory `/tmp/php-4.0.6/Zend' make: *** [all-recursive] Error 1 Do you have any idea what I'm doing wrong? Thanx in advance.