Remove existing built wheels when building source distributions (#559)

This PR modifies the source distribution building to replace any
existing targets after building the new wheel. In some cases, the
existence of an existing target may be indicative of a bug, so we warn.
It's partially a workaround for some (but not all) of the errors in
https://github.com/astral-sh/puffin/issues/554.

crates/puffin-fs/src/lib.rs

@@ -0,0 +1,105 @@
+use std::path::Path;
+
+use tempfile::NamedTempFile;
+
+/// Write `data` to `path` atomically using a temporary file and atomic rename.
+pub async fn write_atomic(path: impl AsRef<Path>, data: impl AsRef<[u8]>) -> std::io::Result<()> {
+    let temp_file = NamedTempFile::new_in(
+        path.as_ref()
+            .parent()
+            .expect("Write path must have a parent"),
+    )?;
+    fs_err::tokio::write(&temp_file, &data).await?;
+    temp_file.persist(&path).map_err(|err| {
+        std::io::Error::new(
+            std::io::ErrorKind::Other,
+            format!(
+                "Failed to persist temporary file to {}: {}",
+                path.as_ref().display(),
+                err.error
+            ),
+        )
+    })?;
+    Ok(())
+}
+
+/// Write `data` to `path` atomically using a temporary file and atomic rename.
+pub fn write_atomic_sync(path: impl AsRef<Path>, data: impl AsRef<[u8]>) -> std::io::Result<()> {
+    let temp_file = NamedTempFile::new_in(
+        path.as_ref()
+            .parent()
+            .expect("Write path must have a parent"),
+    )?;
+    fs_err::write(&temp_file, &data)?;
+    temp_file.persist(&path).map_err(|err| {
+        std::io::Error::new(
+            std::io::ErrorKind::Other,
+            format!(
+                "Failed to persist temporary file to {}: {}",
+                path.as_ref().display(),
+                err.error
+            ),
+        )
+    })?;
+    Ok(())
+}
+
+/// Rename `from` to `to` atomically using a temporary file and atomic rename.
+///
+/// Returns `false` if the `to` path already existed and thus was removed before performing the
+/// rename.
+pub fn rename_atomic_sync(from: impl AsRef<Path>, to: impl AsRef<Path>) -> std::io::Result<bool> {
+    // Remove the destination if it exists.
+    let safe = if let Ok(metadata) = fs_err::metadata(&to) {
+        if metadata.is_dir() {
+            fs_err::remove_dir_all(&to)?;
+        } else {
+            fs_err::remove_file(&to)?;
+        }
+        false
+    } else {
+        true
+    };
+
+    // Move the source file to the destination.
+    fs_err::rename(from, to)?;
+
+    Ok(safe)
+}
+
+/// Copy `from` to `to` atomically using a temporary file and atomic rename.
+///
+/// Returns `false` if the `to` path already existed and thus was removed before performing the
+/// rename.
+pub fn copy_atomic_sync(from: impl AsRef<Path>, to: impl AsRef<Path>) -> std::io::Result<bool> {
+    // Copy to a temporary file.
+    let temp_file =
+        NamedTempFile::new_in(to.as_ref().parent().expect("Write path must have a parent"))?;
+    fs_err::copy(from, &temp_file)?;
+
+    // Remove the destination if it exists.
+    let safe = if let Ok(metadata) = fs_err::metadata(&to) {
+        if metadata.is_dir() {
+            fs_err::remove_dir_all(&to)?;
+        } else {
+            fs_err::remove_file(&to)?;
+        }
+        false
+    } else {
+        true
+    };
+
+    // Move the temporary file to the destination.
+    temp_file.persist(&to).map_err(|err| {
+        std::io::Error::new(
+            std::io::ErrorKind::Other,
+            format!(
+                "Failed to persist temporary file to {}: {}",
+                to.as_ref().display(),
+                err.error
+            ),
+        )
+    })?;
+
+    Ok(safe)
+}