doc/bugs/yaml_setup_file_does_not_support_UTF-8_if_XS_is_installed.mdwn



I converted an ikiwiki setup file to YAML as
[[documented|tips/yaml_setup_files]].
On my Debian Squeeze system, attempting to build the wiki using the
YAML setup file triggers the following error message:
YAML::XS::Load Error: The problem:

    Invalid trailing UTF-8 octet

was found at document: 0
usage: ikiwiki [options] source dest
       ikiwiki --setup configfile

Indeed, my setup file contains UTF-8 characters.
Deinstalling YAML::XS ([[!debpkg libyaml-libyaml-perl]]) resolves this
issue. According to YAML::Any's POD, YAML::Syck is used instead of
YAML::XS in this case since it's the best YAML implementaion available
on my system.
No encoding-related setting is mentionned in YAML::XS' POD. We may
consider there is a bug in there. I'll see if it's known / fixed
somewhere as soon as I get online.
Joey, as a (hopefully) temporary workaround, what do you think of
explicitely using YAML::Syck (or whatever other YAML implementation
that does not expose this bug) rather than letting YAML::Any pick its
preferred one?
--[[intrigeri]]

Upgrading YAML::XS ([[!debpkg libyaml-libyaml-perl]]) to current sid
version (0.34-1) fixes this bug for me. --[[intrigeri]]


libyaml-syck-perl's description mentions that the module is now
deprecated. (I had to do some ugly workaround to make unicode work with
Syck earlier.) So it appears the new YAML::Xs is the
way to go longterm, and presumably YAML::Any will start depending on it
in due course? --[[Joey]]


Right. Since this bug is fixed in current testing/sid, only
Squeeze needs to be taken care of. As far as Debian Squeeze is
concerned, I see two ways out of the current buggy situation:

Add Conflicts: libyaml-libyaml-perl (< 0.34-1~) to the
ikiwiki packages uploaded to stable and squeeze-backports.
Additionally uploading the newer, fixed libyaml-libyaml-perl
to squeeze-backports would make the resulting situation a bit
easier to deal with from the Debian stable user point of view.
Patch the ikiwiki packages uploaded to stable and
squeeze-backports:

either to workaround the bug by explicitly using YAML::Syck
(yeah, it's deprecated, but it's Debian stable)
or to make the bug easier to workaround by the user, e.g. by
warning her of possible problems in case YAML::Any has chosen
YAML::XS as its preferred implementation (the
YAML::Any->implementation module method can come in handy
in this case).


I tend to prefer the first aforementioned solution, but any of
these will anyway be kinda ugly, so...


I was wrong: I just experienced that bug with YAML::XS 0.34-1
too. Gonna report it upstream. --[[intrigeri]]