Configuration goes fine,  libxml2 is detected but when you run make you get:

xml.c:23:10: fatal error: 'libxml/tree.h' file not found

#include <libxml/tree.h>

^

1 error generated.

make[1]: *** [xml.o] Error 1

make: *** [src] Error 2

Workaround for this is to use the --without-xml2 flag because the libxml2
headers don't seem to be installed on El Capitan.