I'm trying to rebuild net-snmp on a hacked-up CentOS 5 machine, which as
lm_sensors-2.10.0-3.1.

This fails with

hardware/sensors/lmsensors_v3.c: In function 'netsnmp_sensor_arch_load':
hardware/sensors/lmsensors_v3.c:21: error: expected '=', ',', ';', 'asm' or '__a
ttribute__' before '*' token
hardware/sensors/lmsensors_v3.c:21: error: 'data' undeclared (first use in this 
function)
hardware/sensors/lmsensors_v3.c:21: error: (Each undeclared identifier is report
ed only once
hardware/sensors/lmsensors_v3.c:21: error: for each function it appears in.)
hardware/sensors/lmsensors_v3.c:22: error: expected '=', ',', ';', 'asm' or
'__attribute__' before '*' token
hardware/sensors/lmsensors_v3.c:22: warning: ISO C90 forbids mixed declarations
and code
hardware/sensors/lmsensors_v3.c:22: error: 'data2' undeclared (first use in this
function)
hardware/sensors/lmsensors_v3.c:23: warning: ISO C90 forbids mixed declarations
and code
hardware/sensors/lmsensors_v3.c:26: error: too many arguments to function
'sensors_get_detected_chips'

etc., etc.

Updating to lm_sensors-3.0.1-5 from rawhide cures this.