Hi Jim,

Have you tried:

      apt-get download libapt-pkg5.0

However libapt-private.so comes from the apt package, same as apt-cache. Your
system is probably borked and needs full reinstall. The kind of error you got is
related to the ABI (yes, with a B), and means that you have a bunch of software
that were compiled against a different version of the library. It also means
that if apt is broken, other softwareq are likely broken too which warrant, as I
said, a full reinstall of your system.

Cheers,
Ludovic

On Mon, 28 Jun 2021, Jim Jackson wrote:

>Hi all,
>
>My Beowulf amd64 system hard drive crashed, and after I'd restored my
>backup I've had problems with apt-get etc.
>
>apt-cache: relocation error:
>/usr/lib/x86_64-linux-gnu/libapt-private.so.0.0: symbol
>_ZN3URIcvNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEB5cxx11Ev
>version APTPKG_5.0 not defined in file libapt-pkg.so.5.0 with link time
>reference
>
>I use rsync for backups, but without the -X -A options, so extended
>attributes and ACLs are lost, don't know if that's the reason. If I need to
>reinstall libapt-pkg5.0 package, does anybody know if it's ok to just to
>use the debian package file?
>
>If not, can anyone tell where I can get the devuan libapt-pkg5.0 package
>file?
>
>cheers
>Jim
>