QGIS » QGIS Application

The known limitation is that QGIS-Server needs a fake X server to render HTML in GetPrint.

We use it in production with getPrint, HTML and fake X server without crashes.

To avoid to use fake X server, QGIS has to use QtWebView headless. It's possible because PhantomJS do it.
http://phantomjs.org/
https://github.com/ariya/phantomjs/

I know that there are workarounds but it's still a serious bug.

This "known limitation" is not really "known" by most part of the users, AFAIK it isn't documented anywhere but in a few old emails, it should be clearly documented instead and we should try to find a system to avoid the crash when an X server isn't available, better serve a blank field instead.

If we cannot find a way to avoid the crash, as a last resource, we should add X to the package dependencies.

-1
To add dependencies
We cannot add x on pur server.
Contestually se font use the getprint .
IT is not a standard wms command
so many wms client dont support iT.
Ask a dependency forma a non standard command mean lost user.
+1 to add clearly to documentation.

Don't know if it's the same issue, but we're getting:

[Thu Jul 31 13:27:07.210983 2014] [fcgid:warn] [pid 5450] (104)Connection reset by peer: [client 127.0.0.1:46153] mod_fcgid: error reading data from FastCGI server
[Thu Jul 31 13:27:07.211444 2014] [core:error] [pid 5450] [client 127.0.0.1:46153] End of script output before headers: qgis_mapserv.fcgi

even after installing and configuring xvfb. This happens quite reliably when attempting to print a layout with layers present in the template legend, but switched off in the TOC.

see also #9763

see also #13285, comment of Giovanni Manghi explains a possible solution:

a solution is here (and I think is also in the manual)

http://www.itopen.it/qgis-server-setup-notes/