From 691ed09a9ba7746ab0bf2ec5aa97d65a72d34960 Mon Sep 17 00:00:00 2001
From: konsti <konstin@mailbox.org>
Date: Wed, 3 Apr 2024 16:02:40 +0200
Subject: [PATCH] Fix windows lock race: Lock exclusive after all try lock
 errors (#2800)

We don't know what kind of error the OS gives us on `try_lock_exclusive`
with an already locked file, so we assume all those errors are an
already locked file and call `lock_exclusive`.

For example the windows error:

```
Os {
    code: 33,
    kind: Uncategorized,
    message: "The process cannot access the file because another process has locked a portion of the file.",
}
```

Fixes #2767
---
 crates/uv-fs/src/lib.rs | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/crates/uv-fs/src/lib.rs b/crates/uv-fs/src/lib.rs
index 468e7d44e..e7d44a882 100644
--- a/crates/uv-fs/src/lib.rs
+++ b/crates/uv-fs/src/lib.rs
@@ -4,7 +4,7 @@ use std::path::{Path, PathBuf};
 use fs2::FileExt;
 use fs_err as fs;
 use tempfile::NamedTempFile;
-use tracing::{error, warn};
+use tracing::{debug, error, warn};
 
 use uv_warnings::warn_user;
 
@@ -282,18 +282,26 @@ pub struct LockedFile(fs_err::File);
 impl LockedFile {
     pub fn acquire(path: impl AsRef<Path>, resource: impl Display) -> Result<Self, std::io::Error> {
         let file = fs_err::File::create(path.as_ref())?;
+        debug!("Trying to lock if free: {}", path.as_ref().user_display());
         match file.file().try_lock_exclusive() {
             Ok(()) => Ok(Self(file)),
-            Err(err) if err.kind() == std::io::ErrorKind::WouldBlock => {
+            Err(err) => {
+                // Log error code and enum kind to help debugging more exotic failures
+                debug!("Try lock error, waiting for exclusive lock: {:?}", err);
                 warn_user!(
                     "Waiting to acquire lock for {} (lockfile: {})",
                     resource,
                     path.user_display(),
                 );
-                file.file().lock_exclusive()?;
+                file.file().lock_exclusive().map_err(|err| {
+                    // Not an fs_err method, we need to build our own path context
+                    std::io::Error::new(
+                        std::io::ErrorKind::Other,
+                        format!("Could not lock {}: {}", path.as_ref().user_display(), err),
+                    )
+                })?;
                 Ok(Self(file))
             }
-            Err(err) => Err(err),
         }
     }
 }