Rpi 4 / Ubuntu Server / openFrameworks

I’ve installed Ubuntu Server on Rpi 4 (already supported) and I’m now trying to install openframeworks.
everything goes well until ./compileOF.sh script
the output is

config.shared.mk:86: *** recipe commences before first target. Stop.
there has been a problem compiling Debug OF library

any ideas of how to proceed?
Thank you

Now I’ve tried with github install but ./download_libs.sh script returns an error when it tries to download a file called


from this url