`buf lint` doesn't allow `field_mask` rule for `google.protobuf.FieldMask` in `buf` 1.62.1

[lberrymage]

GitHub repository with your minimal reproducible example (do not leave this field blank or fill out this field with "github.com/bufbuild/buf" or we will automatically close your issue, see the instructions above!)

https://github.com/lberrymage/buf-lint-error-reproducer

Commands

buf lint

Output

example/v1/some_message.proto:9:45:Field "field_mask" is of type google.protobuf.FieldMask but has (buf.validate.field).field_mask rules.

Expected Output

I expected no lint failures.

Anything else?

The described failures are exhibited with Buf 1.62.1. Buf 1.61.0 works correctly and reports no lint failures.

[fchimpan]

I investigated this issue and found the likely root cause.

In buf v1.62.0, the protovalidate dependency was updated (6865c8df) to version 20251209175733-2a1774d88802, which introduced FieldMaskRules (bufbuild/protovalidate#429).

However, the lint check logic in private/buf/buflint/buflintvalidate/field.go has not been updated to recognize this new rule type, leading to the false positive.

Workaround: Until this is officially supported, you can suppress the error by adding a lint ignore comment:

// buf:lint:ignore PROTOVALIDATE
google.protobuf.FieldMask field_mask = 1 [(buf.validate.field).field_mask = {...}];

[doriable]

Thank you for reporting this, a fix has been put up -- once merged, it will be available on release!

[lberrymage]

Awesome, thanks for the quick fix!