Discovery: Refactor and add Avahi DBus backend

.devcontainer/Dockerfile

@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1
 ARG debian_version=slim-bookworm
-ARG rust_version=1.74.0
+ARG rust_version=1.75.0
 FROM rust:${rust_version}-${debian_version}
 
 ARG DEBIAN_FRONTEND=noninteractive

.github/workflows/test.yml

@@ -109,7 +109,7 @@ jobs:
       matrix:
         os: [ubuntu-latest]
         toolchain:
-          - "1.74" # MSRV (Minimum supported rust version)
+          - "1.75" # MSRV (Minimum supported rust version)
           - stable
         experimental: [false]
         # Ignore failures in beta
@@ -164,7 +164,7 @@ jobs:
       matrix:
         os: [windows-latest]
         toolchain:
-          - "1.74" # MSRV (Minimum supported rust version)
+          - "1.75" # MSRV (Minimum supported rust version)
           - stable
     steps:
       - name: Checkout code
@@ -215,7 +215,7 @@ jobs:
           - aarch64-unknown-linux-gnu
           - riscv64gc-unknown-linux-gnu
         toolchain:
-          - "1.74" # MSRV (Minimum supported rust version)
+          - "1.75" # MSRV (Minimum supported rust version)
           - stable
     steps:
       - name: Checkout code

CHANGELOG.md

@@ -10,11 +10,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - [core] The `access_token` for http requests is now acquired by `login5`
+- [core] MSRV is now 1.75 (breaking)
+- [discovery] librespot can now be compiled with multiple MDNS/DNS-SD backends
+  (avahi, dns_sd, libmdns) which can be selected using a CLI flag. The defaults
+  are unchanged (breaking).
 
 ### Added
 
 - [core] Add `login` (mobile) and `auth_token` retrieval via login5
 - [core] Add `OS` and `os_version` to `config.rs`
+- [discovery] Added a new MDNS/DNS-SD backend which connects to Avahi via D-Bus.
 
 ### Removed
 

COMPILING.md

@@ -56,6 +56,17 @@ On Fedora systems:
 sudo dnf install alsa-lib-devel
 ```
 
+### Zeroconf library dependencies
+Depending on the chosen backend, specific development libraries are required.
+
+*_Note this is an non-exhaustive list, open a PR to add to it!_*
+
+| Zeroconf backend   | Debian/Ubuntu                | Fedora                            | macOS       |
+|--------------------|------------------------------|-----------------------------------|-------------|
+|avahi               |                              |                                   |             |
+|dns_sd              | `libavahi-compat-libdnssd-dev pkg-config` | `avahi-compat-libdns_sd-devel` |   |
+|libmdns (default)   |                              |                                   |             |
+
 ### Getting the Source
 
 The recommended method is to first fork the repo, so that you have a copy that you have read/write access to. After that, it’s a simple case of cloning your fork.