Observer - Panic

[Texnomic]

System information

erigon version 2022.04.4-alpha-f3065a11

Linux ethereum-erigon2 5.4.0-109-generic # 123-Ubuntu SMP Fri Apr 8 09:10:54 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

Steps to reproduce the behaviour

./observer --chain mainnet --datadir /mnt/data

Trace

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x1201262]

goroutine 125 [running]:
github.com/ledgerwatch/erigon/cmd/observer/observer.(*Crawler).Run.func1()
        github.com/ledgerwatch/erigon/cmd/observer/observer/crawler.go:310 +0x102
created by github.com/ledgerwatch/erigon/cmd/observer/observer.(*Crawler).Run
        github.com/ledgerwatch/erigon/cmd/observer/observer/crawler.go:304 +0x1185

[AskAlexSharov]

@battlmonstr take a look pls
just some comment:
about CountPingErrors - better use if err != nil pattern, all other patters often lead to mistakes. I'm about:

	if resultAny == nil {
		return nil, err
	}

[battlmonstr]

@Texnomic thanks for the report.
It is fixed now on the devel branch. Please rebuild from there.

@AskAlexSharov I somehow decided that (nil, nil) is a valid output there, but forgot to check for it. I didn't notice, because all of my recent tests were not starting from scratch 😓