From 8c99ea5c4408d7367c1cb48197bb258da9f81081 Mon Sep 17 00:00:00 2001
From: finch <finch@oxidecomputer.com>
Date: Mon, 10 Aug 2026 10:20:13 -0400
Subject: [PATCH] Replace unmaintained fs2 with fs4 for illumos support

fs2 0.4 has no cfg arm for target_os = "illumos" (the target split out
of "solaris" after fs2's last release), so cargo-mutants does not build
there. fs4 is the maintained fork of fs2 with the same flock-based
locking and support for current targets; the sync feature alone
suffices.

fs4's try_lock_exclusive returns Ok(false) for a held lock instead of
Err(EWOULDBLOCK), so the wait loop now distinguishes contention (keep
polling) from real errors (propagate with context) rather than retrying
forever on any error.

Also drops the ancient kernel32-sys and winapi 0.2 transitive
dependencies that fs2 pulled in on Windows.
---
 Cargo.lock    | 13 ++++++-------
 Cargo.toml    |  2 +-
 src/output.rs | 12 ++++++------
 3 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index dd1fa8b3..bd8d5ed1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -171,7 +171,7 @@ dependencies = [
  "fastrand",
  "filetime",
  "flickzeug",
- "fs2",
+ "fs4",
  "globset",
  "ignore",
  "indoc",
@@ -507,14 +507,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
 
 [[package]]
-name = "fs2"
-version = "0.4.0"
+name = "fs4"
+version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "237b7991317b8d94391c0a4813b1f74fd81c11352440cd598d2b763ed288bfc1"
+checksum = "8640e34b88f7652208ce9e88b1a37a2ae95227d84abec377ccd3c5cfeb141ed4"
 dependencies = [
- "kernel32-sys",
- "libc",
- "winapi 0.2.8",
+ "rustix 1.1.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index 90aeff93..48789b12 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -36,7 +36,7 @@ ctrlc = { version = "3.4", features = ["termination"] }
 fastrand = "2"
 filetime = "0.2.27"
 flickzeug = "0.4.5"
-fs2 = "0.4"
+fs4 = { version = "0.13", default-features = false, features = ["sync"] }
 globset = "0.4.16"
 ignore = "0.4.23"
 indoc = "2.0.0"
diff --git a/src/output.rs b/src/output.rs
index c9c7e151..e3668196 100644
--- a/src/output.rs
+++ b/src/output.rs
@@ -10,7 +10,7 @@ use std::thread::sleep;
 use std::time::Duration;
 
 use camino::{Utf8Path, Utf8PathBuf};
-use fs2::FileExt;
+use fs4::fs_std::FileExt;
 use jiff::Timestamp;
 use path_slash::PathExt;
 use serde::Serialize;
@@ -61,12 +61,12 @@ impl LockFile {
             .open(&lock_path)
             .context("open or create lock.json in existing directory")?;
         let mut first = true;
-        while let Err(err) = lock_file.try_lock_exclusive() {
+        while !lock_file
+            .try_lock_exclusive()
+            .context("try to lock lock.json")?
+        {
             if first {
-                info!(
-                    "Waiting for lock on {} ...: {err}",
-                    lock_path.to_slash_lossy()
-                );
+                info!("Waiting for lock on {} ...", lock_path.to_slash_lossy());
                 first = false;
             }
             check_interrupted()?;