flutter Text exception - expression is not a valid compile-time constant

Constants (i.e. const) in Dart are compile-time, that is, they must not rely on the runtime of your application in anyway, and can only be simple side-effect free constructor invocations (i.e. const constructors) or literals like strings, numbers, and lists/maps.

For example, this is a compile-time string:

const version = 'v1.0.0';

And I could use it below:

const Text(version)

Dart supports limited expressions as well, as compile-time constants:

const Text('My version is: $version')

However in your example, text is not a compile-time constant.

Lets view this through a simpler example, called showMyName:

Widget showMyName(String name) => const Text(name);

This will get an identical error to what you saw, because we're trying to create a compile-time constant Text from a runtime provided value (the argument name). Of course, we don't need Text to be a compile-time constant. You can simply use new:

Widget showMyName(String name) => new Text(name);

In future versions of Dart (with --preview-dart-2), you can omit new:

Widget showMyName(String name) => Text(name);