Caddy exits with 'panic: runtime error: invalid memory address or nil pointer dereference'

[lowercasename]

Caddy 2 has been running flawlessly on my server for a few months, serving about 10 websites. A few hours ago it exited with the following output (apologies for the screenshot, I don't have access to a text console at the moment):

For searching, the relevant output is:

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x2d8 pc=0x8be0e1]
goroutine 778762 [running]:
github.com/caddyserver/certmagic.(*Cache).updateOCSPStaples
[...]
github.com/caddyserver/certmagic.(*Cache).maintainAssets
[...]
github.com/caddyserver/certmagic.NewCache
[...]
caddy.service: Main process exited, code=exited, status=2/INVALIDARGUMENT

The server is running Ubuntu 20.04, and I installed Caddy from the Ubuntu package.

I restarted the service and it's working absolutely fine now, so it seems like it was a once-off, but I'd like to prevent it from happening again!

[mholt]

Which version are you running? I think this was fixed a while ago. I'll need the exact version in order to look up the stack trace.

[mholt]

I just had a great idea, we should be printing the Caddy version in the logs (pictured above)!

[lowercasename]

Ah, good catch, caddy was being held back from updating for some reason! I was running 2.0.0! Now updated to 2.1.1.

[francislavoie]

Thanks for confirming, I'll close this now.

I figure @mholt doesn't need this issue open to remind him to add that extra log line 😅

[mholt]

Yeah, thanks, simple enough: 68529e2

And the bug was fixed upstream back in May: caddyserver/certmagic@5ed3640#diff-52c596c82713259b4527325d2a6c2846 - first by fixing the actual cause of the panic, then adding recover() everywhere so that even if there are other crashes it won't cause the server to go down. So this can't happen again.