Here's the configure line that I used:
./configure --prefix=/opt/lighttpd-1.4.15
Here's the last output from the compiler before it died:
bash-3.00# make
make all-recursive
Making all in src
make[1]: Entering directory `/tmp/lighttpd-1.4.15/src'
/bin/sh ../libtool --tag=CC --mode=compile gcc -DHAVE_CONFIG_H -DLIBRARY_DIR="\"/opt/lighttpd-1.4.15/lib\"" -I. -I.. -D_REENTRANT -DEXTENSIONS -I/opt/pware/include -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGE_FILES -g -O2 -Wall -W -Wshadow -pedantic -std=gnu99 -MT mod_webdav_la-mod_webdav.lo -MD -MP -MF .deps/mod_webdav_la-mod_webdav.Tpo -c -o mod_webdav_la-mod_webdav.lo test -f 'mod_webdav.c' || echo './'mod_webdav.c
gcc -DHAVE_CONFIG_H -DLIBRARY_DIR=\"/opt/lighttpd-1.4.15/lib\" -I. -I.. -D_REENTRANT -DEXTENSIONS -I/opt/pware/include -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGE_FILES -g -O2 -Wall -W -Wshadow -pedantic -std=gnu99 -MT mod_webdav_la-mod_webdav.lo -MD -MP -MF .deps/mod_webdav_la-mod_webdav.Tpo -c mod_webdav.c -o mod_webdav_la-mod_webdav.o
mod_webdav.c: In function 'webdav_delete_file':
mod_webdav.c:536: warning: unused parameter 'p'
mod_webdav.c: In function 'webdav_copy_file':
mod_webdav.c:664: warning: unused parameter 'p'
mod_webdav.c: In function 'webdav_has_lock':
mod_webdav.c:1153: warning: unused parameter 'srv'
mod_webdav.c:1153: warning: unused parameter 'con'
mod_webdav.c:1153: warning: unused parameter 'p'
mod_webdav.c:1153: warning: unused parameter 'uri'
mod_webdav.c: In function 'mod_webdav_subrequest_handler':
mod_webdav.c:1705: error: 'struct <anonymous>' has no member named 'mmap64'
mod_webdav.c:1713: error: 'struct <anonymous>' has no member named 'mmap64'
mod_webdav.c:1720: error: 'struct <anonymous>' has no member named 'mmap64'
mod_webdav.c:1728: error: 'struct <anonymous>' has no member named 'mmap64'
make[1]: *** [mod_webdav_la-mod_webdav.lo] Error 1
make[1]: Leaving directory `/tmp/lighttpd-1.4.15/src'
make: *** [all-recursive] Error 1
make: 1254-004 The error code from the last command is 2.
Stop.