Steps to reproduce

Go to any package that inherits from CMakePackage and override the build_type variant. If you look at the resulting spack info <package>, it turns the When column into [, ] instead of the normal --.

Error message

N/A

Information on your system

N/A

General information

• I have run spack debug report and reported the version of Spack/Python/Platform
• I have searched the issues of this repo and believe this is not a duplicate
• I have run the failing commands in debug mode and reported the output