在执行php -v 或者有时编译一个东西或输入某个命令的时候会出现：
Cannot find module (MTA-MIB): At line 0 in (none)
Cannot find module (NETWORK-SERVICES-MIB): At line 0 in (none)
Cannot find module (SNMPv2-TC): At line 15 in /usr/share/snmp/mibs/UCD-DISKIO-MIB.txt
Did not find 'DisplayString' in module #-1 (/usr/share/snmp/mibs/UCD-DISKIO-MIB.txt)
Did not find 'ucdExperimental' in module UCD-SNMP-MIB (/usr/share/snmp/mibs/UCD-DISKIO-MIB.txt)
Unlinked OID in UCD-DISKIO-MIB: ucdDiskIOMIB ::= { ucdExperimental 15 }
Undefined identifier: ucdExperimental near line 19 of /usr/share/snmp/mibs/UCD-DISKIO-MIB.txt
Cannot find module (SNMPv2-TC): At line 15 in /usr/share/snmp/mibs/LM-SENSORS-MIB.txt
Did not find 'DisplayString' in module #-1 (/usr/share/snmp/mibs/LM-SENSORS-MIB.txt)
Did not find 'ucdExperimental' in module UCD-SNMP-MIB (/usr/share/snmp/mibs/LM-SENSORS-MIB.txt)
Unlinked OID in LM-SENSORS-MIB: lmSensors ::= { ucdExperimental 16 }
Undefined identifier: ucdExperimental near line 32 of /usr/share/snmp/mibs/LM-SENSORS-MIB.txt
Cannot find module (HOST-RESOURCES-MIB): At line 0 in (none)
Cannot find module (HOST-RESOURCES-TYPES): At line 0 in (none)
Cannot find module (SNMPv2-MIB): At line 0 in (none)
Cannot find module (IF-MIB): At line 0 in (none)
Cannot find module (IP-MIB): At line 0 in (none)
Cannot find module (TCP-MIB): At line 0 in (none)
Cannot find module (UDP-MIB): At line 0 in (none)
Cannot find module (NOTIFICATION-LOG-MIB): At line 0 in (none)
Cannot find module (DISMAN-EVENT-MIB): At line 0 in (none)
Cannot find module (DISMAN-SCHEDULE-MIB): At line 0 in (none)
Did not find 'ucdavis' in module UCD-SNMP-MIB (/usr/share/snmp/mibs/UCD-DEMO-MIB.txt)
Unlinked OID in UCD-DEMO-MIB: ucdDemoMIB ::= { ucdavis 14 }
Undefined identifier: ucdavis near line 7 of /usr/share/snmp/mibs/UCD-DEMO-MIB.txt
Cannot find module (SNMP-TARGET-MIB): At line 0 in (none)
Cannot find module (SNMP-FRAMEWORK-MIB): At line 9 in /usr/share/snmp/mibs/NET-SNMP-AGENT-MIB.txt
Cannot find module (SNMPv2-SMI): At line 8 in /usr/share/snmp/mibs/NET-SNMP-MIB.txt
Did not find 'enterprises' in module #-1 (/usr/share/snmp/mibs/NET-SNMP-MIB.txt)
Unlinked OID in NET-SNMP-MIB: netSnmp ::= { enterprises 8072 }
以为少了什么模块，看网上有人贴出这样的答案：
sudo apt-get remove php5-snmp
是 remove 掉了snmp模块，这样就不会出现，不过会不会出现后续的 bug 还需验证