Upgrade to rust stable

[ulrichard]

I'm trying to compile bitcoin-pro, which depends on rust-glade.
On debian testing, installing a couple of packages got me across the first compiler errors. But it still fails on glade.

• libglib2.0-dev
• libcairo2-dev
• libgdk-pixbuf-2.0-dev
• libatk1.0-dev
• libpango1.0-dev
• libgtk-3-dev

on debian testing with rustc 1.48.0:
error[E0554]: #![feature] may not be used on the stable release channel
--> /home/richi/.cargo/registry/src/github.com-1ecc6299db9ec823/glade-0.1.0-alpha.4/src/lib.rs:15:1
|
15 | #![feature(try_trait)]
| ^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to previous error

For more information about this error, try rustc --explain E0554.
error: could not compile glade.

On ubuntu 21.04 with rustc 1.55:
--> /home/richi/.cargo/registry/src/github.com-1ecc6299db9ec823/glade-0.1.0-alpha.4/src/error.rs:22:25
std::option::NoneError not found in std::option

When I try to compile rust-glade master on the ubuntu machine, I get the same error as listed above under debian testing.

[ulrichard]

Yeah, found the culprit:
https://doc.rust-lang.org/std/option/struct.NoneError.html
Any idea how long it will take for this to be available in the stable compiler? Looks like the issue has been open for four years:
rust-lang/rust#42327

[ulrichard]

I run into the same problem when I try with docker: https://github.com/pandoracore/bitcoin-pro/blob/master/contrib/docker-builder/README.md

[dr-orlovsky]

Yeah, because of NoneError this library is nightly-only. Rust stabilization of this feature has being stucked in endless debates on a proper way of doing Try trait, and this year they refactored everything once again, and I assume it will take till about end of the year to get it into stable (I assume they will add it to the 2021 edition).

Nevertheless I am targeting to remove this feature dependency, so in my next round when I will be working on bitcoin pro I will fix this. For now, just compile after running rustup default nightly and that's all