[dartdev] `dart build` should run `pub get` automatically

[dcharkes]

When you haven't run pub get, but run dart build

Then it doesn't complain but creates an empty assets folder

Which is very confusing

[dcharkes]

I cannot reproduce this @mosuem.

dart build on a clean checkout of https://github.com/dart-lang/native/tree/main/pkgs/hooks/example/build/native_add_app works as intended.

Also https://github.com/dart-lang/sdk/blob/main/pkg/dartdev/test/native_assets/build_test.dart does no pub get.

Could you provide a reproduction?

[mosuem]

git clone git@github.com:dart-lang/i18n.git
cd pkgs/intl4x/example/
dart build cli

then it does print

The `dart build cli` command is in preview at the moment.
See documentation on https://dart.dev/interop/c-interop#native-assets.

Deleting output directory: /home/mosum/projects/i18n/pkgs/intl4x/example/build/cli/linux_x64/.
Running build hooks... 
Running link hooks... 
Generated: /home/mosum/projects/i18n/pkgs/intl4x/example/build/cli/linux_x64/bundle/bin/example

but

tree build/

build/
└── cli
    └── linux_x64
        └── bundle
            └── bin
                └── example

5 directories, 1 file

so no assets are built, as the hooks are not really run.

If we run dart pub get first, the build hooks are actually run:

tree build/

build/
└── cli
    └── linux_x64
        └── bundle
            ├── bin
            │   └── example
            └── lib
                └── libicu4x.so

6 directories, 2 files

[dcharkes]

$ ls -lah build/cli/macos_arm64/bundle/lib/
-rwxr-xr-x  1 dacoharkes  primarygroup    29M Oct 13 16:28 libicu4x.dylib

$ /Users/dacoharkes/src/dart-lang/i18n/pkgs/intl4x/example/build/cli/macos_arm64/bundle/bin/example
en
13
July 1, 2024, 8:50 AM Central European Summer Time

$ dart --version
Dart SDK version: 3.10.0-268.0.dev (dev) (Wed Oct 1 09:03:20 2025 -0700) on "macos_arm64"

On Linux:

$ tree build/
build/
`-- cli
    `-- linux_x64
        `-- bundle
            |-- bin
            |   `-- example
            `-- lib
                `-- libicu4x.so

$ build/cli/linux_x64/bundle/bin/example
und
13
July 1, 2024, 8:50 AM Central European Summer Time

$ dart --version
Dart SDK version: 3.10.0-edge (main) (Unknown timestamp) on "linux_x64

This does not reproduce for me. What Dart version are you running on?

[dcharkes]

Oh, apparently the last version has an NPE.

$ dart --version
Dart SDK version: 3.11.0-16.0.dev (dev) (Fri Oct 10 17:03:14 2025 -0700) on "macos_arm64"

$ flutter clean
Deleting build...                                                    1ms
Deleting .dart_tool...                                               2ms

$ dart build cli
The `dart build cli` command is in preview at the moment.
See documentation on https://dart.dev/interop/c-interop#native-assets.

Null check operator used on a null value
#0      BuildCliSubcommand.run (package:dartdev/src/commands/build.dart:184)
<asynchronous suspension>
#1      CommandRunner.runCommand (package:args/command_runner.dart:212)
<asynchronous suspension>
#2      DartdevRunner.runCommand (package:dartdev/dartdev.dart:265)
<asynchronous suspension>
#3      runDartdev (package:dartdev/dartdev.dart:51)
<asynchronous suspension>
#4      main (file:///Volumes/Work/s/w/ir/x/w/sdk/pkg/dartdev/bin/dartdev.dart:13)
<asynchronous suspension>

caused by

The directory `/Users/dacoharkes/src/dart-lang/i18n/pkgs/intl4x/example/bin/example.dart` does not exist.