rust-peg dependency preventing v0.19.0 release

[thanethomson]

We can't release v0.19.0 of tendermint-rpc as it currently stands because of its dependency on unreleased changes in rust-peg. See

tendermint-rs/rpc/Cargo.toml

Line 69 in d1c8877

peg = { git = "https://github.com/kevinmehall/rust-peg.git", rev = "ba6019539b2cf80289190cbb9537c94113b6b7d1" }

I originally pinned the dependency to this commit due to the need for kevinmehall/rust-peg#245 to be released, but it's not clear when a new crate's going to be published.

As such, cargo publish fails for tendermint-rpc v0.19.0 at this point.

We have several options to solve this at present:

1. Strip out the query parsing entirely. This will also mean we'd need to remove the Tendermint RPC CLI, or at least the part of it that depends on query parsing. This option is probably the easiest and quickest in the short term.
2. Try to get rust-peg to work with its latest released version (v0.6.3 from July 2020). I'm least confident about this option.
3. Replace rust-peg with a stable version of a different parser, e.g. nom or LALRPOP. I'm relatively confident I could replace the parser, but it's probably going to take some time to figure out how to use a new parsing library.

Delaying the release is unfortunately not an option.

What's the definition of "done" for this issue?

When we can complete the v0.19.0 release: #854

[thanethomson]

Closed in #858