panic: reflect.Value.Call: call of nil function

[duj4]

The following program sample.go triggers an unexpected result

package main

func main() {
cmap.Upsert()
}

Expected result

There should be no error coming out.

Got

Error like "panic: reflect.Value.Call: call of nil function" posted, which caused the pod reboot.

Yaegi Version

0.16.1

Additional Notes

I am writing a Traefik plugin with https://github.com/orcaman/concurrent-map/tree/v1.0.0 imported. However, error like below posted while it is running for while:

Code snippet is as below: