## Summary
- When running `bun <file>` on a file with an unsupported type (e.g.,
`.css`, `.yaml`, `.toml`), Bun now shows a helpful error message instead
of the misleading "File not found"
- Tracks when a file is resolved but has a loader that can't be run
directly
- Shows the actual file path and file type in the error message
**Before:**
```
error: File not found "test.css"
```
**After:**
```
error: Cannot run "/path/to/test.css"
note: Bun cannot run css files directly
```
## Test plan
- [x] Added regression test in `test/regression/issue/1365.test.ts`
- [x] Test verifies unsupported files show "Cannot run" error
- [x] Test verifies nonexistent files still show "File not found"
- [x] Test fails with `USE_SYSTEM_BUN=1` and passes with debug build
Fixes#1365🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>
