ld-elf.so.1: /usr/local/lib/libglib-2.0.so.0: Undefined symbol "environ"

[Graham Perrin]

grahamperrin at momh167-gjp4-8570p:~ % date ; uname -v
Wed Dec 26 10:18:52 GMT 2018
FreeBSD 13.0-CURRENT r342466 GENERIC-NODEBUG
grahamperrin at momh167-gjp4-8570p:~ % iridium
ld-elf.so.1: /usr/local/lib/libglib-2.0.so.0: Undefined symbol "environ"
grahamperrin at momh167-gjp4-8570p:~ % pkg query '%o %v %R' iridium-browser
www/iridium 2018.5.67_6 FreeBSD
grahamperrin at momh167-gjp4-8570p:~ %

Any ideas?

TIA