Clamav - BBS

安裝clamav出現error

../libclamav/.libs/libclamav.so: undefined reference to `pthread_cleanup_pop'
../libclamav/.libs/libclamav.so: undefined reference to `pthread_cleanup_push'
*** Error code 1

Stop in /usr/ports/security/clamav/work/clamav-0.86.2/clamscan.
*** Error code 1

Stop in /usr/ports/security/clamav/work/clamav-0.86.2.
*** Error code 1

Stop in /usr/ports/security/clamav/work/clamav-0.86.2.
*** Error code 1

Stop in /usr/ports/security/clamav.
*** Error code 1

Stop in /usr/ports/security/clamav.

我用的是freebsd 5.1 + sendmail

這是哪裡的問題呢?
該如何解決?感謝!

--