> flutter pub global activate dart_repl
The current Dart SDK version is 2.7.0.
Because pub global activate depends on dart_repl any which requires SDK version >=1.0.0 <2.0.0, version solving failed.
pub finished with exit code 1
It's only a very minimal implementation as I only need basic expression handling for the project that I wrote this for but hopefully the Gist might help those who would like to update this package to work with current version of Dart and vm service.