FYI: successful installation of VirtualBox 6.1.26 and Vagrant 2.2.18 on Windows 10

As Dror Mikdash mentioned below for macOS, you do not need to downgrade VirtualBox to 6.0.x any more.

In fact, doing so “broke” an existing VirtualBox VM - I think because 6.0 conflicts with Windows Subsystem for Linux. Uninstalling WSL resolved the conflict - but was probably unnecessary if I had just stayed with 6.1 in the first place!

Also, when adding “C:\MinGW\msys\1.0\bin” to your PATH variable, place it on a separate line.
rsync did not work with it appended to PATH with a semicolon as show in the lecture notes.

Hope that helps.

BTW, I had originally installed WSL so I could use rsync to create backups; the MinGW rsync command works just as well for my needs.

e.g. To create a backup copy of your C:\Users directory structure, run something like:
rsync -arv --delete /c/Users/ /e/c_drive/Users/

From memory, in WSL it would be:
rsync -arv --delete /mnt/c/Users/ /mnt/e/c_drive/Users/