Cannot use `pub` with --preview-dart-2

[kevmoo]

> DART_VM_OPTIONS=--preview-dart-2 pub 
Invalid isolate state - Unable to make it runnable

On Dart VM version: 2.0.0-dev.26.0 (Thu Feb 15 03:06:13 2018 +0100) on "macos_x64"

[kevmoo]

CC @a-siva @nex3 @zanderso

[a-siva]

in the dart sdk builds pub, analyzer, dart2js and ddc use an application snapshot to run, these snapshots are built in dart 1 mode. When preview-dart-2 is specified it is not compatible with these snapshots and hence the failure. The error message is not very helpful and we will fix that.

To get these command with --preview-dart-2 first the pub, dart2js, analyzer code needs to be made strong mode clean and these application snapshots need to be generated with that option turned on. I think we planned to do this in Q2.

The issue that the original bug wanted addressed was a way for folks to run tests in preview-dart-2 mode using pub. For this to work 'pub run' needs to implement the --preview-dart-2 option so that it starts the test process using this option, somewhat similar to the '-c' or '--checked' option that it currently supports.

sivalinuxmach[sdk]>out/ReleaseX64/dart-sdk/bin/pub run --help
Run an executable from a package.

Usage: pub run [args...]
-h, --help Print this usage information.
-c, --[no-]checked Enable runtime type checks and assertions.
--mode Mode to run transformers in.
(defaults to "release" for dependencies, "debug" for entrypoint)

[a-siva]

Who needs to own this issue of implementing the option '--preview-dart-2' in 'pub run' ?
Not sure who owns pub these days.

[kevmoo]

@nex3 still does most of the work, although it's migrating slowly to AAR w/ @mit-mit driving

[mit-mit]

We have no plans, or bandwidth, to work on pub client in q1.

[dgrove]

@nex3 @grouma @natebosch Can you all figure out what's needed here?