2.9 was a semver-major breakage

[kornelski]

protobuf 2.9 release has broken prometheus 0.7.

Could you yank it and re-release it as 3.0?

[tomaka]

It has also broken libp2p: libp2p/rust-libp2p#1259

[stepancheg]

It has also broken libp2p: libp2p/rust-libp2p#1259

.proto files need to be regenerated.

[stepancheg]

With prometheus the issue is the same: .proto files need to be regenerated.

Do you think that generated files must be backwards compatible? Because it would make backwards-compatible changes in protobuf practically impossible.

[Ekleog]

What about saying “from now on .proto files need to be generated from build.rs” and release what currently is 2.9 as 3.0 with this additional caveat?

[stepancheg]

Yanked the version.

[stepancheg]

This new version is incompatible only in generated code, all human-written code stays compatible.

How about releasing version 2.9 with making all previously generated files emit a warning about code need to be regenerated? (Copy all functions to new names, and make old names deprecated)

And release 2.10 with new features in a couple of weeks?

[tomaka]

What would be wrong with releasing 3.0 instead?

[stepancheg]

@tomaka don't have enough large features implemented to release 3.0.

[kornelski]

That's not what semver means. It doesn't increment on features, it increments on any incompatibilities.

[dayfine]

When will this be re-released? I actually want to use 2.9

[fbernier]

@stepancheg If you plan on having other releases before 3.0, could we add back the rest of the non-breaking stuff that was in 2.9.0 such as json printing?

[stepancheg]

Reflection changes won't be ported to version 2, because of multiple backwards compatibility issues.

Now I'm preparing to release rust-protobuf version 3.

This is the master task: #518

The new release is a good place to fix various API issues, so feedback is highly appreciated.