# ./main.go:12:9: undefined: foo.Bar

- **ID:** `go/undefined-symbol`
- **Domain:** go
- **Category:** build_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

The identifier does not exist in the imported package (renamed, unexported, or the wrong package version). Often after a dependency upgrade.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 1.x | active | — | — |

## Workarounds

1. **** (90% success)
   ```
   go doc github.com/foo/bar.Bar
go doc github.com/foo/bar | grep -i bar
   ```
2. **** (85% success)
   ```
   go get github.com/foo/bar@v1.2.0
go mod tidy
   ```

## Dead Ends

- **** — the symbol still does not exist in that package (95% fail)
- **** — undefined symbols are compile errors, not vet warnings (100% fail)
- **** — invalid syntax; cannot shadow package members (100% fail)