`Error: ambiguous config file format; please specify adapter (use --adapter)` since 2.8.2

[foux]

Hello, Since 2.8.2 my Caddy doesn't starts with the error Error: ambiguous config file format; please specify adapter (use --adapter)

I get the meaning of the error and why I get it (Caddy couldn't detect the language without ambiguities). What I'm not getting is how I can pass the Adapter option. I'm running Caddy on debian through systemd, and is there a way to pass this adatper without having to override the systemd unit file (for exemple an entry in the Caddyfile itself) ?

Thanks for your help. Here is my current very simple Caddyfile :

my.fdn.site {
        reverse_proxy 127.0.0.1:8080
}

[encbladexp]

I have the same issue, but creating a system override file "fixed" it as a workaround for now:

# /etc/systemd/system/caddy.service.d/override.conf
[Service]
ExecStart=
ExecStart=/usr/bin/caddy run --adapter caddyfile --environ --config /etc/caddy/Caddyfile
ExecReload=
ExecReload=/usr/bin/caddy reload --adapter caddyfile --config /etc/caddy/Caddyfile --force

[foux]

I though about it, but I would prefer not creating an override, because it would also override any future way of starting Caddy. I'll go that way if there's no alternative, but I'd like to be sure there isn't one before ;)

[francislavoie]

This will be fixed by https://github.com/caddyserver/caddy/pull/6362

[foux]

This will be fixed by https://github.com/caddyserver/caddy/pull/6362

Thanks! I'll do the override in the meantime. Keeping the issue open for others till it's fixed

[33b5e5]

This just hit me on Ubuntu 24.04 LTS. I noticed Caddy was no longer running after the (automated) update of the pkg.

[crazyuploader]

Affected here as well, Caddy stopped starting suddenly after package updates

[TillW99]

Same Problem here, dont want to override so ich will stay at 2.7.6 - hope it get fixed as soon as possible

[xxf185]

2.8.2 Same startup failure

[mohammed90]

Those of you experiencing it, you can test the fix by downloading the CI artifacts from here: https://github.com/caddyserver/caddy/actions/runs/9337830397

[bsinou]

I observed the same yesterday on Debian 12, after simple apt update / upgrade. I could workaround using the tip from @encbladexp (thx!)

This morning,"apt upgrade" brought the 2.8.4:

• could remove the workaround
• everything is working flawlessly again.

Thanks for the quick fix (and the overall nice work)!!