+>> Modifying `getconfig` is not a valid solution, because IkiWiki.pm is also imported by
+>> [[ikiwiki-transition]], [[ikiwiki-calendar]], the regression tests, etc.
+>>
+>> The way I would personally do it is to have a new non-exported function `getlibdirs`
+>> or something, have it do something like this:
+>>
+>> if (! ref $config{libdir}) {
+>> if (length $config{libdir}) {
+>> $config{libdir} = [$config{libdir}];
+>> } else {
+>> $config{libdir} = [];
+>> }
+>> }
+>> return @{$config{libdir}};
+>>
+>> and replace all uses of $config{libdir} with it.
+>>
+>> --[[smcv]]
+>>>
+>>> I implemented it (see branch ``paternal/libdirs``). I used [[smcv]]'s idea, but
+>>> avoiding side effects. I edited documentation as well. As usual, as neither
+>>> English nor Perl are my first languages (damn! I would be so much more
+>>> efficient in Python) feel free to improve my [[!taglink patch]].
+>>> [[!template id=gitbranch branch=spalax/paternal/libdirs browse="https://github.com/paternal/ikiwiki/tree/paternal/libdirs" author="[[Louis|spalax]]"]]
+
+>>>> While reviewing and applying your patch I decided the new
+>>>> "sometimes a list, sometimes not" behaviour of `libdir` was
+>>>> too confusing in documentation, so I made it work like underlaydir(s)
+>>>> instead: ikiwiki will now search each item of `$config{libdirs}`, then
+>>>> `$config{libdir}`. [[done]] --[[smcv]]
+
+>>>>> Good. I cannot see any justification apart from historical reasons, but I
+>>>>> agree with your choice.
+>>>>> -- [[Louis|spalax]]