library versions in pkgsrc binaries

[steve%prd.co.uk@localhost (Steve Blinkhorn)]

I currently have two servers running in production mode at a remote
data centre.  For reasons discussed in this list back in May/June,
they are currently running 8.0_RC1.

I need to get a browser running on one of them, so I tried to pkg_add - u -u
firefox60 using as PKG_PATH ..../x86_64/8.0_2018Q1/All.  This version
complained that libstdc++.so.8 was not found.   So I tried using
..../x86_64/7.0_2018Q1/All, and got the complaint that libfreetype.so.18
was not found.

In the past I have had issues with perl modules requiring other
modules in a seemingly endless chain, requiring a lot of manual
intervention.

Is there some trick I am missing getting packages to download and run
in the simple way apparently envisaged, or is there something broken
about the way dependencies are managed?   I would prefer to think the
former...

-- 
Steve Blinkhorn <steve%prd.co.uk@localhost>