Migrating SOAP Proxy clients to 2.0 with a 1.9 Server gives empty @INC errors

Concerned version

Version: %2.0.7

Platform: Apache

Summary

When updating lemonldap handler to 2.0 from a previous 1.9 install, I Get the following error:

SOAP error : Failed to access class (Lemonldap::NG::Common::PSGI::SOAPService): Can't locate Lemonldap/NG/Common/PSGI/SOAPService.pm in @INC (you may need to install the Lemonldap::NG::Common::PSGI::SOAPService module) (@INC contains:) at (eval 12931) line 2.

I modified the apache vhost config has to have he following lines:

    PerlOptions +GlobalRequest
    PerlModule Lemonldap::NG::Handler::ApacheMP2
    PerlHeaderParserHandler Lemonldap::NG::Handler::ApacheMP2

I tried to move the first two lines outside of vhost as explained in the doc but there is no difference.

I obtain the same error when running /usr/share/lemonldap-ng/bin/purgeLocalCache with the same empty @INC

Printing @INC in the _soapCall sub of SOAP.pm gives me the following content:

/etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.28.1 /usr/local/share/perl/5.28.1 /usr/lib/x86_64-linux-gnu/perl5/5.28 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl/5.28 /usr/share/perl/5.28 /usr/local/lib/site_perl /usr/lib/x86_64-linux-gnu/perl-base

configuration part of lemonldap-ng.ini contains the following:

type         = SOAP
proxy        = https://auth.evok.ch/index.pl/config

localStorage=Cache::FileCache
localStorageOptions={                             \
    'namespace'          => 'lemonldap-ng-config',\
    'default_expires_in' => 600,                  \
    'directory_umask'    => '007',                \
    'cache_root'         => '/tmp',               \
    'cache_depth'        => 0,                    \
}

Logs

[Thu Feb 20 13:55:02.542993 2020] [perl:debug] [pid 7977:tid 140195441665792] Apache2.pm(14): Check configuration for Lemonldap::NG::Handler::ApacheMP2::Main
SOAP error : Failed to access class (Lemonldap::NG::Common::PSGI::SOAPService): Can't locate Lemonldap/NG/Common/PSGI/SOAPService.pm in @INC (you may need to install the Lemonldap::NG::Common::PSGI::SOAPService module) (@INC contains:) at (eval 22479) line 2.
[Thu Feb 20 13:55:02.696757 2020] [perl:error] [pid 7977:tid 140195441665792] Lemonldap::NG::Handler::ApacheMP2::Main: Unable to load configuration: Lemonldap::NG::Common::Conf::Backends::SOAP loaded.\nError: No configuration available in backend.\nError: No configuration found in local cache
[Thu Feb 20 13:55:02.696846 2020] [perl:error] [pid 7977:tid 140195441665792] Lemonldap::NG::Handler::ApacheMP2::Main: No configuration found

Backends used

Backend is a 1.9.21 on Debian Jessie installed through lemonldap 1.9 repo type is SOAP Works with all 1.9 clients but none of the 2.0 clients. As suggested in the upgrade doc, I want to upgrade the clients (I have ~20 of them) before upgrading the backend.

Possible fixes