–– Pkl Error ––
Type constraint `let (myself: Listing<Bird> = this)
      myself[0].name == "Sandy"` violated.
Value: new Listing { new Bird { name = "Bob" }; new Bird { name = ? } }

x | let (myself: Listing<Bird> = this)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
at constraintDetails2#birds (file:///$snippetsDir/input/errors/constraintDetails2.pkl)

x | new {
    ^^^^^
at constraintDetails2#birds (file:///$snippetsDir/input/errors/constraintDetails2.pkl)

xxx | renderer.renderDocument(value)
      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
at pkl.base#Module.output.text (pkl:base)

xxx | if (renderer is BytesRenderer) renderer.renderDocument(value) else text.encodeToBytes("UTF-8")
                                                                         ^^^^
at pkl.base#Module.output.bytes (pkl:base)
