error calling MarshalJSON / unsupported value: NaN

Hello, I am facing an issue trying to set up the prometheus-to-sd container.

This is the container config in the deployment:
```yaml
- name: prometheus-to-sd
image: gcr.io/google-containers/prometheus-to-sd:v0.9.2
ports:
- name: profiler
containerPort: 6060
command:
- /monitor
- --stackdriver-prefix=custom.googleapis.com
- --monitored-resource-type-prefix=k8s_
- --source=:http://localhost:9253
- --pod-id=$(POD_NAME)
- --namespace-id=$(POD_NAMESPACE)
- --cluster-location=REDACTED
resources:
requests:
cpu: 10m
limits:
cpu: 10m
env:
- name: POD_NAME
valueFrom:
fieldRef:
fieldPath: metadata.name
- name: POD_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespace
```

And this is the php-fpm exporter container:

```yaml
- name: fpm-metrics
image: hipages/php-fpm_exporter
imagePullPolicy: IfNotPresent
ports:
- name: exporter
containerPort: 9253
env:
# FastCGI address where FPM listens on, we're connecting over TCP
- name: PHP_FPM_SCRAPE_URI
value: "tcp://localhost:9000/fpm-status"
# Enabled to calculate process numbers via php-fpm_exporter since PHP-FPM sporadically reports wrong active/idle/total process numbers.
- name: PHP_FPM_FIX_PROCESS_COUNT
value: "true"
# Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal] (default "error")
- name: PHP_FPM_LOG_LEVEL
value: info
resources:
requests:
cpu: 20m
memory: 32Mi
limits:
cpu: 20m
memory: 32Mi
```

I can see the fpm-metrics container working, since I have set up proxy pass in the nginx container to forward /metrics to the fpm-metrics container on port 9253 just as a test, and I can see some data when accessing it.

The logs from the prometheus-to-sd container after running for 15-30 minutes:
```
I0629 12:00:06.326609 1 main.go:121] GCE config: &{REDACTED}
I0629 12:00:06.326701 1 main.go:182] Taking source configs from flags
I0629 12:00:06.326714 1 main.go:184] Taking source configs from kubernetes api server
I0629 12:00:06.326722 1 main.go:124] Built the following source configs: [0xc000390270]
I0629 12:00:06.425637 1 main.go:193] Running prometheus-to-sd, monitored target is http://localhost:9253
E0629 12:02:10.025888 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:03:06.926664 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:03:07.125572 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:04:07.426957 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:05:10.625747 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:05:10.626850 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:05:21.354563 1 stackdriver.go:60] Error while sending request to Stackdriver googleapi: Error 503: Deadline expired before operation could complete., backendError
E0629 12:06:07.325596 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:06:09.525891 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:07:06.926569 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:08:07.226769 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:09:07.225912 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:10:07.326342 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:10:20.652022 1 stackdriver.go:60] Error while sending request to Stackdriver googleapi: Error 503: Deadline expired before operation could complete., backendError
E0629 12:11:07.626358 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:11:07.726183 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:12:07.726443 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:12:08.825681 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:13:07.425616 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:13:08.926036 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:14:07.825910 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:14:08.925774 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:15:09.026367 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:15:19.644443 1 stackdriver.go:60] Error while sending request to Stackdriver googleapi: Error 503: Deadline expired before operation could complete., backendError
E0629 12:16:07.226192 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:16:09.526655 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:17:08.025625 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:18:07.826717 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:18:09.726555 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:19:06.926358 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:20:08.826345 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:21:07.326439 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:21:07.425685 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:22:06.927493 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:22:08.126282 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
E0629 12:23:09.226728 1 stackdriver.go:60] Error while sending request to Stackdriver json: error calling MarshalJSON for type *monitoring.CreateTimeSeriesRequest: json: error calling MarshalJSON for type *monitoring.TimeSeries: json: error calling MarshalJSON for type *monitoring.Point: json: error calling MarshalJSON for type *monitoring.TypedValue: json: error calling MarshalJSON for type *monitoring.Distribution: json: unsupported value: NaN
```

I have googled but have come up empty handed, and the closest issue I could find was from 2018-2019 and hasn't had any activity in a long time. So thought I would try here.

I apologize if this is the wrong place to ask or if it has been resolved I just hadn't found it.

Hope someone is able to help. Thanks in advance.