Apply suggestions from code review

Co-authored-by: Bailey Hayes <ricochet@users.noreply.github.com>

Author: mkatychev

crates/wasm-pkg-core/src/lock.rs

@@ -48,6 +48,9 @@ impl PartialEq for LockFile {
         self.packages == other.packages && self.version == other.version
     }
 }
+/// Compares a [`LockFile`] against a `(version, packages)` snapshot. This is used to
+/// detect whether a build would mutate the lock file (e.g. before publishing) without
+/// having to hold a second [`LockFile`].
 impl PartialEq<(u64, BTreeSet<LockedPackage>)> for LockFile {
     fn eq(&self, other: &(u64, BTreeSet<LockedPackage>)) -> bool {
         self.packages == other.1 && self.version == other.0

crates/wkg/src/main.rs

@@ -285,8 +285,12 @@ impl PublishArgs {
                 });
             }
 
+            // Sanitize the package ref for use as a filename prefix: `namespace:name`
+            // contains characters (`:`, `/`) that are invalid in filenames on some
+            // platforms (notably Windows).
+            let prefix: String = build_ref.to_string().replace([':', '/'], "_");
             let tmp = tempfile::Builder::new()
-                .prefix(&build_ref.to_string())
+                .prefix(&prefix)
                 .suffix(".wasm")
                 .tempfile()
                 .context("Failed to create temporary file for built WIT package")?;