Current clisp distribution unbundled libffcall
and libsigsegv. Unfortunatly, many popular
Linux distributions do not include them.
When libffcall and/or libsigsegv are installed
in a nonstandard directory clisp-2.47 configure
can not find them. Giving --with-libsigsegv-prefix
(which is mentioned in unix/INSTALL) does not
help -- apparently this argument is ignored by
configure. For ffcall I was unable to find
official method to specify alternative location.
Also modifying CFLAGS and/or LDFLAGS did not
help: adding -I to CFLAGS allowed to find
header files, but when I modified LDFLAGS,
then configure was able to find the libraries,
but subconfigure in i18n failed, complaining
about modified LDFLAGS.