升级system后，登录时提示出错，注释掉/etc/login.defs里对应的行就行了。

gentoo /etc/login.defs

You have updated your Gentoo system but you did not fix the cfg-file as you should. Either you know how to fix it in another way, or simply just du the "mv -f ._cfg0000_login.defs login.defs". See an example below: 

joe@home ~$ su - Password: configuration error - unknown item 'FAILLOG_ENAB' (notify administrator) configuration error - unknown item 'LASTLOG_ENAB' (notify administrator) configuration error - unknown item 'MOTD_FILE' (notify administrator) configuration error - unknown item 'FTMP_FILE' (notify administrator) configuration error - unknown item 'ENV_ROOTPATH' (notify administrator) configuration error - unknown item 'PASS_MIN_LEN' (notify administrator) configuration error - unknown item 'CHFN_AUTH' (notify administrator)  root@home ~# cd /etc root@home etc# mv -f ._cfg0000_login.defs login.defs