Thank you Heitbaum, now ldd shows that all the linked libraries can be found.
Amending the LD_LIBRARY_PATH to include the libpcloudcc_lib.so gets pcloudcc to work.
Thank you!
LD_LIBRARY_PATH='/usr/bin:/usr/sbin:/storage/.kodi/addons/virtual.network-tools/bin:/storage/backup'
raspi:~/backup # ./pcloudcc -h
pCloud console client v.2.0.1
Allowed options:
-h [ --help ] produce help message
-u [ --username ] arg pCloud account name
-p [ --password ] Ask pCloud account password
-c [ --crypto ] Ask crypto password
-y [ --passascrypto ] arg Use user password as crypto password also.
-d [ --daemonize ] Daemonize the process.
-o [ --commands ] Parent stays alive and processes commands.
-m [ --mountpoint ] arg Mount point where drive to be mounted.
-k [ --commands_only ] Daemon already started pass only commands
-n [ --newuser ] Switch if this is a new user to be registered.
-s [ --savepassword ] Save password in database.
So to summarise for whoever comes next:
- compile pcloudcc on Raspberry Pi OS changing the setting for the correct processor
- copy pcloudcc and libpcloudcc_lib.so to somewhere in the storage filesystem
- install the network tools and system tools add-ons
- amend LD_LIBRARY_PATH to include the pcloud library
- reboot
Thanks again for your help!