Regarding (2), which Linux distribution did you see this on? And did anything useful get written to logs/error_log ?

That was AlmaLinux. I don't remember exactly about errors in Nginx logs. But this error usually means that either a service isn't running or something is misconfigured under /cgi-bin location in a server config.

Did you only see this on AlmaLinux?

Did you only see this on AlmaLinux?

I see it on both Alma 9 and Ubuntu 22.04 with Nginx.

However, I just found a "problem", as when you run scripts under Nginx it returns damn super confusing error (502 bad gateway), unless you don't print first print "Content-Type: text/html\n\n"; or even print " \n\n"; works which makes it even more ridiculous.

i.e. test.cgi and fcgiwrap with Apache and the following works:

#!/usr/bin/perl

print "Hello World";

However, under Nginx it prints misleading error in ~/logs/fcgiwrap.log:

Cannot get script name, are DOCUMENT_ROOT and SCRIPT_NAME (or SCRIPT_FILENAME) set and is the script executable?

.. which makes absolutely no sense! It took me some time to understand what was really wrong. However, just "sending headers" with print "Content-Type: text/html\n\n"; makes it work with Nginx as well:

#!/usr/bin/perl

print "Content-Type: text/html\n\n";
print "Hello World";

.. and more ridiculous this works too:

#!/usr/bin/perl

print " \n\n";
print "Hello World";

.. but why? And isn't that sick that the error message produced is so misleading? I know it's not our problem but still.

That's kind of expected - all CGI scripts must output proper headers. If not, the fcgiwrap server probably just fails to process the output and returns an error to Nginx.

As for issue #3, it should be fixed by 7e65268

That's kind of expected - all CGI scripts must output proper headers.

Yes, yes I'm aware of that but the error message is deceptive!

As for issue #3, it should be fixed by 7e65268

That works, thanks!