mod_proxy_html v3.1.2 fails to install on Solaris10

[Igor Cicimov <icicimov@xxxxxxxxx>]

# /usr/local/apache2/bin/apxs -c -I/usr/local/include/libxml2 -i -a mod_proxy_html.c
/usr/local/apache2/build/libtool --silent --mode=compile gcc -prefer-pic   -DSOLARIS2=10 -D_POSIX_PTHREAD_SEMANTICS -D_REENTRANT -D_LARGEFILE64_SOURCE -g -O2 -I/usr/local/apache2/include  -I/usr/local/apache2/include   -I/usr/local/apache2/include  -I/usr/local/include/libxml2  -c -o mod_proxy_html.lo mod_proxy_html.c && touch mod_proxy_html.slo
mod_proxy_html.c:66:25: mod_xml2enc.h: No such file or directory
mod_proxy_html.c: In function `proxy_html_filter':
mod_proxy_html.c:904: error: `ENCIO_OUTPUT' undeclared (first use in this function)
mod_proxy_html.c:904: error: (Each undeclared identifier is reported only once
mod_proxy_html.c:904: error: for each function it appears in.)
mod_proxy_html.c: In function `mod_proxy_html':
mod_proxy_html.c:1215: error: `apr_OFN_xml2enc_charset_t' undeclared (first use in this function)
mod_proxy_html.c:1215: error: syntax error before ')' token
mod_proxy_html.c:1216: error: `apr_OFN_xml2enc_filter_t' undeclared (first use in this function)
mod_proxy_html.c:1216: error: syntax error before ')' token
mod_proxy_html.c: In function `proxy_html_insert':
mod_proxy_html.c:1230: error: `ENCIO_INPUT_CHECKS' undeclared (first use in this function)
apxs:Error: Command failed with rc=65536

The apache is 2.2.13 and the apr is apache built in. Any suggestions?

Thanks,

Igor