Make sure to update your package manager and other packages.
I've updated both, and even restarted, but the version remains the same. My system doesn't know any newer versions:
protobuf-compiler is already the newest version (3.6.1.3-2+rpi1)
Then it probably depends on the Linux version you're running.
What I tried and sent you before, was on Ubuntu 20.04 LTS, as I figured Raspibolt is Debian or Ubuntu based.
Can you try these commands to figure out what you're running?
lsb_release -a
cat /etc/os-release
hostnamectl
root$ sudo apt install plocate
Did you perhaps mean
sudo apt install locate? There's no package by the name "plocate". Also, I don't get anything in return when I run the locate command. Maybe it only works on OpenSUSE? Absolutely nothing:
root@raspibolt:/home/bitcoin# locate libprotobuf
root@raspibolt:/home/bitcoin#
(I've installed the locate package)Then, a whole bunch of stuff is actually completely missing. You need the protobuf compiler and libraries.