Conflicting help texts for node_cpu_frequency_hertz

[jjegg01]

Hi,

we noticed an error message every time the Node exporter metrics endpoint is hit on our HPC cluster when enabling --collector.cpu.info:

level=ERROR source=http.go:175 msg="error gathering metrics: 192 error(s) occurred:
* [from Gatherer #2] collected metric node_cpu_frequency_hertz label:{name:"cpu" value:"0"} gauge:{value:2.4e+09} has help "Current CPU thread frequency in hertz." but should have "CPU frequency in hertz from /proc/cpuinfo."
[repeating for all other cores]

Weirdly enough, this only seems to happen on nodes with a relatively high amount of cores (192 in the case above), but not for our smaller nodes. Also, the metric node_cpu_frequency_hertz is exported just fine with Current CPU thread frequency in hertz as the help text. My Go knowledge is basic at best, but it seems a bit strange to me that cpufreq_common.go and cpu_linux.go seem to define a Desc with the same FQName, but with different help texts:

node_exporter/collector/cpu_linux.go

Lines 102 to 106 in b9b6820

	cpuFrequencyHz: prometheus.NewDesc(
	prometheus.BuildFQName(namespace, cpuCollectorSubsystem, "frequency_hertz"),
	"CPU frequency in hertz from /proc/cpuinfo.",
	[]string{"package", "core", "cpu"}, nil,
	),

node_exporter/collector/cpufreq_common.go

Lines 23 to 27 in b9b6820

	cpuFreqHertzDesc = prometheus.NewDesc(
	prometheus.BuildFQName(namespace, cpuCollectorSubsystem, "frequency_hertz"),
	"Current CPU thread frequency in hertz.",
	[]string{"cpu"}, nil,
	)

The error indeed disappears when the two help texts are the same, but I don't know if that only fixes the symptom or if a better fix would be to avoid the FQName duplication in the first place.

Details about test environment

• Tested with both the EPEL version of node-exporter for Rocky Linux 9 and a fresh build against the master branch:

node_exporter, version 1.11.1 (branch: tarball, revision: 1.el9)
  build user:
  build date:       20260407
  go version:       go1.25.8 (Red Hat 1.25.8-1.el9_7)
  platform:         linux/amd64
  tags:             rpm_crashtraceback,libtrust_openssl,netgo,osusergo,static_build

node_exporter, version  (branch: , revision: b9b6820db7e125a4666280cedb2c3abcd45f9327-modified)
  build user:
  build date:
  go version:       go1.25.7
  platform:         linux/amd64
  tags:             unknown

• The error message appears on a dual-socket AMD EPYC 9654 node with 192 cores, but not on a dual-socket Intel Xeon Gold 6140 node with 36 cores.
• Full commandline of node-exporter (the port was changed to avoid interfering with the normal monitoring):

prometheus-node-exporter --web.listen-address=127.0.0.1:8100 --collector.cpu.info