+ cd /var/local/git/grpc-dart/interop
+ /usr/lib/dart/bin/pub get --verbose
FINE: Pub 2.7.2
MSG : Resolving dependencies...
SLVR: fact: interop is 0.0.0
SLVR: derived: interop
SLVR: fact: interop requires SDK version >=2.8.0 <3.0.0
SLVR: conflict: interop requires SDK version >=2.8.0 <3.0.0
SLVR: Version solving took 0:00:00.045882 seconds.
    | Tried 1 solutions.
FINE: Resolving dependencies finished (0.052s).
ERR : The current Dart SDK version is 2.7.2.
    |
    | Because interop requires SDK version >=2.8.0 <3.0.0, version solving failed.
FINE: Exception type: SolveFailure
FINE: package:pub/src/solver/version_solver.dart 308:5   VersionSolver._resolveConflict
    | package:pub/src/solver/version_solver.dart 131:27  VersionSolver._propagate
    | package:pub/src/solver/version_solver.dart 96:9    VersionSolver.solve
    | ===== asynchronous gap ===========================
    | dart:async                                         Future.catchError
    | package:pub/src/utils.dart 109:52                  captureErrors.<fn>
    | package:stack_trace                                Chain.capture
    | package:pub/src/utils.dart 122:11                  captureErrors
    | package:pub/src/command_runner.dart 171:13         PubCommandRunner.runCommand
+ /usr/lib/dart/bin/pub get --verbose
FINE: Pub 2.7.2
MSG : Resolving dependencies...
SLVR: fact: interop is 0.0.0
SLVR: derived: interop
SLVR: fact: interop requires SDK version >=2.8.0 <3.0.0
SLVR: conflict: interop requires SDK version >=2.8.0 <3.0.0
SLVR: Version solving took 0:00:00.041042 seconds.
    | Tried 1 solutions.
FINE: Resolving dependencies finished (0.048s).
ERR : The current Dart SDK version is 2.7.2.
    |
    | Because interop requires SDK version >=2.8.0 <3.0.0, version solving failed.