On the off chance the NSPrincipalClass (SWIFT-118) doesn't apply to the macOS command line, we'll need to manually call MongoSwift.initialize() for the test runner. This may be similar to what was done in LinuxMain (SWIFT-72).
SWIFT-72mongoc_init and mongoc_cleanup are never called
is related to
SWIFT-118Assign test setup classes to NSPrincipalClass