I installed Ubuntu 18.04 on a Raspberry Pi 3 B+ and WiringPi following the instructions presented here. The problem is that when calling the GPIO utility, I get the following error:

Why is it unable to find the hardware revision number? Is there something I can do to make it work?

I installed Ubuntu 18.04 on a Raspberry Pi 3 B+ and WiringPi following the instructions presented here. The problem is that when calling the GPIO utility, I get the following error:

It seems that the hardware line is missing from /proc/cpuinfo:

processor       : 0
model name      : ARMv7 Processor rev 4 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32 
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xd03
CPU revision    : 4

Is there something I can do to make it work? Can I modify the cpuinfo file, or there is no solution other than using another linux image?