Editing EPrints 3.4.3 (section)

==== Requesting /cgi/set_lang causes an internal server error ====
This is cause by an underlying error where there is no <code>scheme</code> method for <code>Apache2::RequestRec</code> object.  Instead <code>EPrints::Repository</code>'s <code>get_secure</code> method should be called and tested for whether the return value is the string "on".  [https://github.com/eprints/eprints3.4/commit/8c18cd49c65597539bd3fe9c1c97ef05c52694f7 This patch] can be used to fix this issue.  However, the original intent for this change in 3.4.3 is to ensure EPrints' <code>set_lang</code> [https://hacks.mozilla.org/2020/08/changes-to-samesite-cookie-behavior/ continues to work in future version of Firefox] and other browsers (see https://github.com/eprints/eprints3.4/issues/118).  

Even with the above patch to the fix, EPrints' <code>set_lang</code> may not be correctly defined to be supported in future web browsers.  To make sure it is, you need to make sure that the installed version Perl's <a href="https://metacpan.org/pod/CGI::Cookie"><code>CGI::Cookie</code></a> package is at least version 4.31.  This is the case for Ubuntu (18.04 and 20.04 LTS) and RHEL/CentOS 8, all of which, (as of 2nd June 2021), install version 4.38.  However, RHEL/CentOS 7 only installs version 3.63.  This means you will need to install the latest version through CPAN (as the root user):
 cpan CGI::Cookie