[AnisHerdev]

Summary

Fixes DependencyDiscoverer.discover when source file paths listed in Cargo .d dep-info files contain spaces (e.g. Windows user profile directories like C:\Users\John Doe\... or project paths containing spaces).

Root Cause

Cargo and rustc emit Makefile-compatible dep-info files where spaces within prerequisite paths are escaped using backslashes (\ ).

The previous implementation:

return File(dependencyFilePath)
    .readAsLinesSync()
    .expand((line) => line.trim().split(' ').skip(1))
    .map(path.toUri);

performed a naive .split(' '). For paths containing spaces (e.g. C:\Users\John\ Doe\lib.rs), this broke the single file path into invalid tokens:

• C:\Users\John\
• Doe\lib.rs

When these broken tokens are forwarded to Flutter's native assets hook runner (build_hooks), Flutter treats path tokens ending in separators as directories to watch and attempts directory listing on C:\Users\John\*, crashing the entire build with:

Target build_hooks failed: FileSystemException: Directory listing failed, path = 'C:\Users\John\*' (OS Error: The directory name is invalid, errno = 267)

Solution

1. Normalize Line Continuations: Replaces Make-style line continuations (\ followed by a newline) so multi-line prerequisite rules parse cleanly.
2. Preserve Escaped Spaces: Splits prerequisites using a negative lookbehind regex (?<!\\) +, ensuring that escaped spaces (\ ) inside file paths are not treated as token delimiters.
3. Unescape Prerequisite Paths: Replaces \ with standard spaces before passing each token to path.toUri.
4. Unit Tests: Added test cases in dependency_discoverer_test.dart testing escaped spaces on Windows and POSIX paths, as well as line continuations.

Verification

• dart analyze: 0 issues found (passed very_good_analysis).
• dart format: Fully formatted.
• dart test test/dependency_discoverer_test.dart: All 6 tests passed.

[AnisHerdev]

Note on CI Integration Test Failures

The core build_and_test job passed completely (Rust clippy/fmt/tests, Dart analyze/format, and package unit tests all succeeded).

The failures across the 5 integration test jobs (macos, windows, linux, ios, and android) are unrelated to this PR's changes. All 5 runners failed before test execution during melos run init-integration-test-boilerplate with:

ERROR: Unhandled exception:
Bad state: Could not find global installation of melos:melos.
Platform.script: file:///.../.pub-cache/hosted/pub.dev/melos-8.10.1/bin/melos.dart
Platform.resolvedExecutable: .../dart
This is likely a bug in `package:cli_launcher`.
#0      _findGlobalInstallation (package:cli_launcher/cli_launcher.dart:408:5)
#1      _launchFromGlobalInstallation (package:cli_launcher/cli_launcher.dart:853:30)
#2      launchExecutable (package:cli_launcher/cli_launcher.dart:842:11)
#3      main (file:///.../.pub-cache/hosted/pub.dev/melos-8.10.1/bin/melos.dart:5:52)

Root cause:

• .github/workflows/build.yml uses subosito/flutter-action@v2 without pinning a version, pulling the latest stable release.
• On November 10, Flutter 3.50.0 (with Dart 3.14.0) was released.
• Under Flutter 3.50.0 / Dart 3.14.0, executing init-integration-test-boilerplate (which delegates to nested dart run melos:melos exec ... because melos is a workspace dev_dependency) runs directly from the hosted package cache path (.pub-cache/hosted/...). This path is not recognized as a global installation by package:cli_launcher, throwing an unhandled StateError.
• This same failure reproduces across all concurrent PRs on this repo (e.g. Honor the Android API requested by Rust build hooks #122).

I have intentionally kept this PR strictly scoped to the Cargo dep-info escaped spaces fix without altering workflow files. If helpful, I would be happy to open a separate PR to address the CI runner compatibility (e.g. pinning Flutter or adjusting the Melos script invocation).