Sorry to be the bearer of bad news. I downloaded the latest release (yay!) of SCT as a zip, and then followed the install instructions.
However, the installation fails with the error in the title. Full pastebin here:
I have a working beta 2 version, so this is not urgent, but perhaps I am not the only one with this issue. The beta-2 version works, and sct_check_dependencies returns everything as OK.