Ok, for the record: The right patch applies cleanly but it produces this build error:
# github.com/google/cel-go/cel src/github.com/google/cel-go/cel/env.go:399:12: e.limits undefined (type *Env has no field or method limits) src/github.com/google/cel-go/cel/env.go:399:19: undefined: limitCodePointSize src/github.com/google/cel-go/cel/env.go:416:15: undefined: ErrorAsIssues src/github.com/google/cel-go/cel/env.go:619:15: undefined: ErrorAsIssues So upgrading to the new version looks indeed the preferred course of action here. Thanks.

