[native_assets] Support `dart pub global run` about sdk

[sigurdm]

And I'm thinking, it's probably cleanest to already invoke the build hook to produce the native assets during dart pub global activate and not during dart pub global run. (But we don't precompile the Dart code on activate judging from shell script in bin/.)

We do precompile - except for when the package is global activated from path.

We also support recompilation if the snapshot was compiled with a different VM.

[dcharkes]

Thanks for the report @lindeer!

We don't have support yet for pub global run.

I would have expected the error message to complain that the experiment is required instead of run as if there are no native assets.

Just to double check, everything works fine when doing dart run --enable-experiment=native-assets mylib:mylib?

(Also, transferring this to the Dart SDK repo, as it should be implemented there.)

[dcharkes]

FYI @jonasfj @sigurdm

[dcharkes]

@jonasfj @sigurdm What would be a good way to save the binaries for pub global activated packages produced by the build hook.

And I'm thinking, it's probably cleanest to already invoke the build hook to produce the native assets during dart pub global activate and not during dart pub global run. (But we don't precompile the Dart code on activate judging from shell script in bin/.)

[lindeer]

Just to double check, everything works fine when doing dart run --enable-experiment=native-assets mylib:mylib?

yeah, everything is OK when I run dart run.

[dcharkes]

After some offline discussion with @jonasfj and @sigurdm, this should probably be addressed by dart pub (package:pub) no longer manually compiling Dart to jit snapshots, but by dart pub invoking dart build exe (package:dartdev) so that dartdev is responsible for building dart code and bundling native assets. dart-lang/pub#4313

(Instead of trying to patch what pub is currently doing.)