ponylang
Document `ponyup default` in README
Ideally, for non-default platforms (eg. Linux distros using with glibc < 2.29), users should choose a platform with this command before running ponyup update so that all commands use the same platform. The per-command override --platform is documented near the bottom of the README and can be easily missed during installation, since it will not fail before actually running ponyc; and ideally this command only needs to be run once during setup.
Note: In my specific case (Debian Buster, WSL2, glibc 2.28), setting the platform to ubuntu18.04 solves my problem during installation.
Also do note that ponyup default is mentioned in the README, but specifically when troubleshooting "unable to install ponyc". This issue is for when the installation is successfully, but running the binary later fails due to library mismatches on different platforms.