[Bug] panic: runtime error: invalid memory address or nil pointer dereference

[dmouraneto]

Summary

When under high load, sometimes I get this error

goroutine 17 [running]:
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x58 pc=0x8e7b68]
/go/pkg/mod/github.com/growthbook/growthbook-golang@v0.1.9/growthbook.go:106 +0x25
github.com/growthbook/growthbook-golang.New.func1(0x0?)
/go/pkg/mod/github.com/growthbook/growthbook-golang@v0.1.9/feature_repository.go:92
github.com/growthbook/growthbook-golang.repoUnsubscribe(...)
/go/pkg/mod/github.com/growthbook/growthbook-golang@v0.1.9/feature_repository.go:432 +0x71
github.com/growthbook/growthbook-golang.(*refreshData).removeSubscription(0x131d3c0, 0xc000f30628)
/go/pkg/mod/github.com/growthbook/growthbook-golang@v0.1.9/feature_repository.go:593
github.com/growthbook/growthbook-golang.getKey(...)
/go/pkg/mod/github.com/growthbook/growthbook-golang@v0.1.9/growthbook.go:519 +0x88
github.com/growthbook/growthbook-golang.(*GrowthBook).GetAPIInfo(0xc000f30628)

Here is the library code where the panic is generated:

func (gb *GrowthBook) GetAPIInfo() (string, string) {
	gb.inner.RLock()
	defer gb.inner.RUnlock()

	apiHost := gb.inner.context.APIHost
	if apiHost == "" {
		apiHost = "https://cdn.growthbook.io"
	}

	return strings.TrimRight(apiHost, "/"), gb.inner.context.ClientKey
}

This code is invoked because of GrowthBook finalizer.
Don't know if the GC can collect the context before running the finalizer code and is causing this issue. Not sure what else can turn the context to an invalid state.

Expected Behavior

Don't panic

Current Behavior

panic

[abs]

Hi @dmouraneto - any chance you'd be willing to give https://pkg.go.dev/github.com/growthbook/growthbook-golang@v0.2.0 a try to see if it resolves this issue?

[dmouraneto]

@abs not sure what I did back then but I'm not having the issue anymore.
I'll test this new version and report if I find any issue.