If pkg-config is not installed, picotool cannot find libusb-1.0-0 and the pico_setup.sh fails with an error. I believe this is the simplest fix to solve the issue within Ubuntu 20.04 for Raspberry Pi 4 64-bit.
This is a useful addition, thanks! This patch is needed to run pico_setup.sh in a minimal Debian Bookworm amd64 environment (e.g. the debian:bookworm docker container).
If pkg-config is not installed, picotool cannot find libusb-1.0-0 and the pico_setup.sh fails with an error. I believe this is the simplest fix to solve the issue within Ubuntu 20.04 for Raspberry Pi 4 64-bit.