New message notifications using notify-rust

[cleeyv]

The initial version is just a generic notification every time a message is received. I'm currently testing this with gnome-shell and it is working well. As suggested in the readme, I agree that these notifications should be optional. I imagined doing that with a config in gurk.toml but haven't tried it out yet. I'll probably submit the PR once that part is working.

[cleeyv]

This is ready for review! In the end it is not configured through gurk.toml at all, instead it is disabled by default and is optionally enabled at build time with the cargo argument --feature notifications. It is implemented with rust-notify, which in turn depends on the dbus-rs. I implemented it as an optional cargo build feature because dbus-rs still depends on the C library libdbus for both building and running this functionality. This is also why I had to add some build libdbus-related dependencies to the CI config for the builds to complete successfully.

As far as I can tell, there are two possible alternatives to implementing it as an opt-in cargo feature:

• Include notify-rust by default, and list libdbus-1-dev and pkg-config as build dependencies of the project. This is currently the only viable alternative, and I thought making it optional at compile time was better than requiring more external dependencies (especially for the server use case where there a higher chance that the dbus libraries are not already installed).
• For the future, use a rust-only notifications stack, without external C dependencies. This is being worked on but apparently isn't fully usable yet, see libdbus-sys: consider a Rust-native implementation diwic/dbus-rs#100.

For both of these alternatives, the new message notifications being optional would require it to be configurable at run time (probably through gurk.toml).

I found this PR from the starship repo to be informative for background info starship/starship#1019 because they were also implementing dbus notifications with notify-rust and ran into many of the same issues that I did.

[boxdot]

Thanks for the PR and the investigation! LGTM

[zeenix]

• For the future, use a rust-only notifications stack, without external C dependencies. This is being worked on but apparently isn't fully usable yet, see

Just FYI if you still have the need/desire for a pure D-Bus crate, zbus is at your service. We recently rolled out 2.0, which is primarily async API, The upcoming release (~1 week) will also support Windows platform, provide tighter tokio integration and support for TCP sockets with more auth mechanisms.