Why is vapor cloud deploy failing?

My vapor 4.0.0 xCode 11.4 web server runs fine on localhost:8080. When I check the vapor version at the command line, I get 3.1.10, and when I try to deploy, it fails:

$ vapor version Vapor Toolbox: 3.1.10 $ swift --version Apple Swift version 5.2 (swiftlang-1103.0.32.1 clang-1103.0.32.29) Target: x86_64-apple-darwin19.4.0

$ vapor cloud deploy
app: pg3a

... Selected swift version: 5.2.0 [Failed] Swift version https://omegle.ws 5.2.0 is not supported Error: deploy failed