chore: Fix clippy lints with minimal diff

This is required, since now we're installing `rustfmt` from the latest
state of the fenix repo. This wasn't recent enough for the latest rust
version. The input was locked at (2025-07-02). Now it's up to date.

Cargo.toml

@@ -867,7 +867,7 @@ unused-qualifications = "warn"
 #unused-results = "warn"                                             # TODO
 
 ## some sadness
-elided_named_lifetimes = "allow"                                     # TODO!
+mismatched_lifetime_syntaxes = "allow"                               # TODO!
 let_underscore_drop = "allow"
 missing_docs = "allow"
 # cfgs cannot be limited to expected cfgs or their de facto non-transitive/opt-in use-case e.g.
@@ -1006,3 +1006,6 @@ literal_string_with_formatting_args = { level = "allow", priority = 1 }
 
 
 needless_raw_string_hashes = "allow"
+
+# TODO: Enable this lint & fix all instances
+collapsible_if = "allow"

flake.lock

@@ -153,11 +153,11 @@
         "rust-analyzer-src": "rust-analyzer-src"
       },
       "locked": {
-        "lastModified": 1751525020,
+        "lastModified": 1755585599,
-        "narHash": "sha256-oDO6lCYS5Bf4jUITChj9XV7k3TP38DE0Ckz5n5ORCME=",
+        "narHash": "sha256-tl/0cnsqB/Yt7DbaGMel2RLa7QG5elA8lkaOXli6VdY=",
         "owner": "nix-community",
         "repo": "fenix",
-        "rev": "a1a5f92f47787e7df9f30e5e5ac13e679215aa1e",
+        "rev": "6ed03ef4c8ec36d193c18e06b9ecddde78fb7e42",
         "type": "github"
       },
       "original": {
@@ -546,11 +546,11 @@
     "rust-analyzer-src": {
       "flake": false,
       "locked": {
-        "lastModified": 1751433876,
+        "lastModified": 1755504847,
-        "narHash": "sha256-IsdwOcvLLDDlkFNwhdD5BZy20okIQL01+UQ7Kxbqh8s=",
+        "narHash": "sha256-VX0B9hwhJypCGqncVVLC+SmeMVd/GAYbJZ0MiiUn2Pk=",
         "owner": "rust-lang",
         "repo": "rust-analyzer",
-        "rev": "11d45c881389dae90b0da5a94cde52c79d0fc7ef",
+        "rev": "a905e3b21b144d77e1b304e49f3264f6f8d4db75",
         "type": "github"
       },
       "original": {

flake.nix

@@ -31,13 +31,17 @@
           inherit system;
         };
 
+        fnx = inputs.fenix.packages.${system};
         # The Rust toolchain to use
-        toolchain = inputs.fenix.packages.${system}.fromToolchainFile {
+        toolchain = fnx.combine [
+          (fnx.fromToolchainFile {
             file = ./rust-toolchain.toml;
 
             # See also `rust-toolchain.toml`
-          sha256 = "sha256-KUm16pHj+cRedf8vxs/Hd2YWxpOrWZ7UOrwhILdSJBU=";
+            sha256 = "sha256-+9FmLhAOezBZCOziO0Qct1NOrfpjNsXxc/8I0c7BdKE=";
-        };
+          })
+          fnx.complete.rustfmt
+        ];
 
         mkScope =
           pkgs:

rust-toolchain.toml

@@ -9,13 +9,16 @@
 # If you're having trouble making the relevant changes, bug a maintainer.
 
 [toolchain]
-channel = "1.87.0"
 profile = "minimal"
+channel = "1.89.0"
 components = [
     # For rust-analyzer
     "rust-src",
     "rust-analyzer",
     # For CI and editors
-    "rustfmt",
     "clippy",
+    # you have to install rustfmt nightly yourself (if you're not on NixOS)
+    #
+    # The rust-toolchain.toml file doesn't provide any syntax for specifying components from different toolchains
+    # "rustfmt"
 ]

src/api/client/sync/v4.rs

@@ -45,6 +45,7 @@ use crate::{
 type TodoRooms = BTreeMap<OwnedRoomId, (BTreeSet<TypeStateKey>, usize, u64)>;
 const SINGLE_CONNECTION_SYNC: &str = "single_connection_sync";
 
+#[allow(clippy::cognitive_complexity)]
 /// POST `/_matrix/client/unstable/org.matrix.msc3575/sync`
 ///
 /// Sliding Sync endpoint (future endpoint: `/_matrix/client/v4/sync`)

src/core/config/mod.rs

@@ -1,3 +1,4 @@
+#![allow(clippy::doc_link_with_quotes)]
 pub mod check;
 pub mod manager;
 pub mod proxy;

src/core/debug.rs

@@ -100,7 +100,7 @@ pub fn trap() {
 
 #[must_use]
 pub fn panic_str(p: &Box<dyn Any + Send>) -> &'static str {
-	p.downcast_ref::<&str>().copied().unwrap_or_default()
+	(**p).downcast_ref::<&str>().copied().unwrap_or_default()
 }
 
 #[inline(always)]

src/router/serve/unix.rs

@@ -30,7 +30,7 @@ use tower::{Service, ServiceExt};
 
 type MakeService = IntoMakeServiceWithConnectInfo<Router, net::SocketAddr>;
 
-const NULL_ADDR: net::SocketAddr = net::SocketAddr::new(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)), 0);
+const NULL_ADDR: net::SocketAddr = net::SocketAddr::new(IpAddr::V4(Ipv4Addr::UNSPECIFIED), 0);
 const FINI_POLL_INTERVAL: Duration = Duration::from_millis(750);
 
 #[tracing::instrument(skip_all, level = "debug")]