No support for enums 'allow_alias' feature

[andresier]

See: https://developers.google.com/protocol-buffers/docs/proto?csw=1#enum
Proto 2 - Language guide:

You can define aliases by assigning the same value to different enum constants. To do this you need to set the allow_alias option to true, otherwise protocol compiler will generate an error message when aliases are found.

Using: Version 2.4.1.555 (current)
When I attempt to include such an option in my proto, I get the following error:
test.proto(150, 10): error CS9999: Option "allow_alias" unknown.

I suspect this is a known issue, but I saw no mention of it on the current issue list. Thanks.

[jskeet]

As per the top-level readme, this project hasn't attempted to keep up with the newer features of protobuf. It's effectively a legacy project, but you're welcome to fork it if you wish.