Periphery doesn't seem to work with a workspace file.

[david-palmer79]

I'm trying to use periphery with a workspace. I get the error "Target 'MyApp' does not exist in 'MyApp.workspace'". It is my understanding a workspace doesn't have a target. This is the command I'm trying to run:

periphery scan --workspace MyApp.xcworkspace --schemes MyApp --clean-build --retain-public -- "-destination 'platform=iOS Simulator,OS=latest,name=iPhone 11'"

I have verified my app builds with the following command:

xcodebuild clean build -workspace MyApp.xcworkspace -scheme MyApp -destination 'platform=iOS Simulator,OS=latest,name=iPhone 11'

Am I doing something wrong?