[Users] Clawsker doesn't start (Can't locate Gtk3.pm in @INC...)

[Removed GDPR]

Hi,

I have just built Clawsker from git source (the same
way I have been doing for a long time) but it won't
start:

[~]: /opt/clawsker/bin/clawsker
Can't locate Gtk3.pm in @INC (you may need to install the Gtk3 module) (@INC contains: /usr/lib/perl5/site_perl/5.26.1/x86_64-linux-thread-multi /usr/lib/perl5/site_perl/5.26.1 /usr/lib/perl5/vendor_perl/5.26.1/x86_64-linux-thread-multi /usr/lib/perl5/vendor_perl/5.26.1 /usr/lib/perl5/5.26.1/x86_64-linux-thread-multi /usr/lib/perl5/5.26.1 /usr/lib/perl5/site_perl) at /opt/clawsker/bin/clawsker line 22.
BEGIN failed--compilation aborted at /opt/clawsker/bin/clawsker line 22.

How do I fix this please?

FWIW this is an openSUSE Leap 15 system and:

[~]: rpm -q gtk3-devel
gtk3-devel-3.22.30-lp150.3.3.1.x86_64

--
George