unbuffered output does not work

[jum]

if I use the unbuffered output option like this:

cgi /cgi-bin/trace.cgi /usr/lib/cgi-bin/trace.cgi {
        unbuffered_output
}

I see this message in my error log:

Cannot write response without buffer.

apparently the current caddy version does not implement the Flusher interface.

[aksdb]

Is it possible you use http3? You might have to use http1.1 or 2 to have that work.

[jum]

Hmm, I turned off h3 in my servers config and the output is still buffered. The message is still output that there is no buffer.

[aksdb]

I can't reproduce it. It works here with http 1.1, 2.0 and 3.0.

Do you maybe have other plugins installed that intervene or do you otherwise manipulate the middleware chain? Can you maybe retry with a very minimal example?

[egormanga]

Adding a log directive breaks it. Removing it resolves the problem.

Further investigation on logging modes is needed here.

Upd. header causes it too. In fact, any response-manipulating directive probably will.