rrdtool 更新でエラー

Error: could not save png to ...

Well
I will answer self
the proble was with library pango
to resolve that problem need recompile library png, cairo, freetype2, pango in the same order.
when i recompile pango i watch erro about cairo
in /usr/port/UPDATIN i found how to update cairo
portupgrade \*cairo\*
after updating cairo pango was compiled without error.
And finish problem has been resolved.

Thanks to netspider
http://ru-root.livejournal.com/2135057.html

Cacti • View topic - FreeBSD ERROR: could not save png to ''

if (status != CAIRO_STATUS_SUCCESS) {
 rrd_set_error("Could not save png to '%s'", im->graphfile);

rrdtool fails under freebsd 8.1-Stable: ru_root

コンパイルする。

portupgrade -f png
portupgrade -f cairo
portupgrade -f freetype2
portupgrade -f pango
portupgrade -f rrdtool

portupgrade -f munin-master

portupgrade -f gd
portupgrade -f mrtg