Update prost to 0.8

[pingyu]

Update Prost to 0.8, to avoid security issue of 0.7 (RUSTSEC-2021-0073).
Related issue: tikv/tikv#10905, tikv/protobuf-build#55

Note that grpcio-proto still depends on prost 0.7 because of its build-dependency to protobuf-build 0.12. As protobuf-build 0.12 depends on grpcio-compiler 0.9, there is a circular dependency between grps-rs and protobuf-build.

I think we should release grps-rs 0.10.0 first, then protobuf-build 0.13, and at last update grpcio-proto to depend on protobuf-build 0.13.

Signed-off-by: pingyu shui.yu@126.com

[sticnarf]

Well, I think it is okay to release protobuf-build 0.13 first because it allows all recent grpcio-compiler versions.

Then, we can release v0.10 of grpc-rs and grpcio-compiler together.

@BusyJay What do you think?

[BusyJay]

Well, I think it is okay to release protobuf-build 0.13 first because it allows all recent grpcio-compiler versions.

Then, we can release v0.10 of grpc-rs and grpcio-compiler together.

Agree. In long term, we better land #545 to solve the problem completely.

[BusyJay]

Better keep the old version. We will send a standalone PR to mutate the version and update changelog.

[pingyu]

Comment addressed. And change version of depending protobuf-build to >=0.12, to use the coming 0.13 version without modification again.
PTAL~

BTW, why better keep the old version ?

[BusyJay]

Because we may not just include one change in next minor version. This is also friendly for people who want to try the change using patch.

[pingyu]

Got it. Thanks~

[BusyJay]

Is there any risk to upgrade to 0.8? I can see a comment here: tokio-rs/prost#526 (comment).

[pymongo]

Is there any risk to upgrade to 0.8? I can see a comment here: tokio-rs/prost#526 (comment).

prost 0.8 Timestamp need TryInto to convert to std::time::SystemTime, before 0.7 can use Into trait to convert

but I think this convert is safe on Linux in prost 0.8

prost <= 0.7 is compile failed on rustc >= 1.56.0