Yes, I should have be more precise: I tried both "xcode-select --install" and installing the command line tools from the package downloaded from the Apple web site.
I still get the same error message, indicating XCode is missing.
To repeat myself from earlier this year:
Does
xcode-select --install
help?
You can also download the SDKs from
developer.apple.com/download/more
(look for ,,Command Line Tools'').