Update flake.lock, Rust toolchain, GHC

flake.nix

@@ -5,7 +5,6 @@
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     crane = {
       url = "github:ipetkov/crane";
-      inputs.nixpkgs.follows = "nixpkgs";
     };
     systems.url = "github:nix-systems/default";
     rust-overlay = {
@@ -52,7 +51,7 @@
           (
             final: prev: {
               # TODO: Bump the Rust version here...
-              rustToolchain = final.pkgsBuildHost.rust-bin.stable."1.72.1".default.override {
+              rustToolchain = final.pkgsBuildHost.rust-bin.stable."1.81.0".default.override {
                 targets =
                   final.lib.optionals final.stdenv.targetPlatform.isDarwin [
                     "x86_64-apple-darwin"
@@ -74,9 +73,6 @@
     # GHC versions to include in the environment for integration tests.
     # Keep this in sync with `./test-harness/src/ghc_version.rs`.
     ghcVersions = [
-      "ghc90"
-      "ghc92"
-      "ghc94"
       "ghc96"
       "ghc98"
     ];

nix/packages/checks/treefmt.nix

@@ -13,7 +13,7 @@ mkCheck {
   ];
 
   checkPhase = ''
-    treefmt --fail-on-change
+    HOME="$PWD" treefmt --fail-on-change
   '';
 
   meta.description = ''

nix/packages/ghciwatch.nix

@@ -1,7 +1,7 @@
 {
   lib,
   stdenv,
-  libiconv,
+  pkgsStatic,
   darwin,
   buildPackages,
   haskell,
@@ -56,10 +56,7 @@
 
       nativeBuildInputs = lib.optionals stdenv.isDarwin [
         # Additional darwin specific inputs can be set here
-        (libiconv.override {
-          enableStatic = true;
-          enableShared = false;
-        })
+        pkgsStatic.libiconv
         darwin.apple_sdk.frameworks.CoreServices
       ];
 

src/clap_markdown/formatter.rs

@@ -283,7 +283,7 @@ where
         if arg.is_positional() {
             let id = arg
                 .get_value_names()
-                .and_then(|names| names.get(0))
+                .and_then(|names| names.first())
                 .map(|name| name.as_str())
                 .unwrap_or_else(|| arg.get_id().as_str());
 

src/ghci/loaded_module.rs

@@ -73,7 +73,7 @@ impl PartialEq for LoadedModule {
 
 impl PartialOrd for LoadedModule {
     fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-        self.path.partial_cmp(&other.path)
+        Some(self.cmp(other))
     }
 }
 

src/ghci/mod.rs

@@ -294,10 +294,7 @@ impl Ghci {
             prompt_patterns: AhoCorasick::from_anchored_patterns([PROMPT]),
         };
 
-        let stdin = GhciStdin {
-            stdin,
-            stderr_sender: stderr_sender.clone(),
-        };
+        let stdin = GhciStdin { stdin };
 
         shutdown
             .spawn("stderr", |shutdown| {

src/ghci/stdin.rs

@@ -3,14 +3,12 @@ use miette::Context;
 use miette::IntoDiagnostic;
 use tokio::io::AsyncWriteExt;
 use tokio::process::ChildStdin;
-use tokio::sync::mpsc;
 use tracing::instrument;
 
 use crate::incremental_reader::FindAt;
 
 use super::loaded_module::LoadedModule;
 use super::parse::ShowPaths;
-use super::stderr::StderrEvent;
 use super::CompilationLog;
 use super::GhciCommand;
 use super::ModuleSet;
@@ -20,8 +18,6 @@ use crate::ghci::GhciStdout;
 pub struct GhciStdin {
     /// Inner stdin writer.
     pub stdin: ChildStdin,
-    /// Channel sender for communicating with the stderr task.
-    pub stderr_sender: mpsc::Sender<StderrEvent>,
 }
 
 impl GhciStdin {

test-harness/Cargo.toml

@@ -12,7 +12,7 @@ fs_extra = "1.3.0"
 futures-util = "0.3.28"
 itertools = "0.11.0"
 miette = { version = "5.9.0", features = ["fancy"] }
-nix = { version = "0.26.2", default_features = false, features = ["process", "signal"] }
+nix = { version = "0.26.2", default-features = false, features = ["process", "signal"] }
 regex = "1.9.4"
 serde = { version = "1.0.186", features = ["derive"] }
 serde_json = "1.0.105"

test-harness/src/fs.rs

@@ -77,6 +77,7 @@ impl Fs {
             }
             OpenOptions::new()
                 .create(true)
+                .append(true)
                 .write(true)
                 .open(path)
                 .await

test-harness/src/ghciwatch.rs

@@ -429,7 +429,7 @@ impl GhciWatch {
     /// Returns the first matching event.
     pub fn assert_logged_in_checkpoint(
         &self,
-        checkpoints: impl CheckpointIndex + Clone,
+        checkpoints: impl CheckpointIndex,
         matcher: impl IntoMatcher,
     ) -> miette::Result<&Event> {
         let mut matcher = matcher.into_matcher()?;

test-harness/src/internal.rs

@@ -16,16 +16,16 @@ use tokio::process::Child;
 thread_local! {
     /// The temporary directory where `ghciwatch` is run. Note that because tests are run with the
     /// `tokio` current-thread runtime, this is unique per-test.
-    pub(crate) static TEMPDIR: RefCell<Option<PathBuf>> = RefCell::new(None);
+    pub(crate) static TEMPDIR: RefCell<Option<PathBuf>> = const { RefCell::new(None) };
 
     /// The GHC version to use for this test. This should be a string like `ghc962`.
     /// This is used to select the correct GHC version to run.
-    pub(crate) static GHC_VERSION: RefCell<String> = RefCell::new(String::new());
+    pub(crate) static GHC_VERSION: RefCell<String> = const { RefCell::new(String::new()) };
 
     /// The `ghciwatch` process for this test.
     ///
     /// This is set so that we can make sure to kill it when the test ends.
-    pub(crate) static GHCIWATCH_PROCESS: RefCell<Option<Child>> = RefCell::new(None);
+    pub(crate) static GHCIWATCH_PROCESS: RefCell<Option<Child>> = const { RefCell::new(None) };
 }
 
 /// Wraps an asynchronous test with startup/cleanup code.

test-harness/src/tracing_json.rs

@@ -30,7 +30,7 @@ pub struct Event {
 
 impl Event {
     /// Get an iterator over this event's spans, from the outside in (root to leaf).
-    pub fn spans(&self) -> impl Iterator<Item = &Span> + DoubleEndedIterator {
+    pub fn spans(&self) -> impl DoubleEndedIterator<Item = &Span> {
         self.spans.iter().chain({
             // The `new`, `exit`, and `close` span lifecycle events aren't emitted from inside the
             // relevant span, so the span isn't listed in `spans`. Instead, the relevant span is in