fix(cli): prevent drive letters from being confused with namespaces i…

…n Windows.

The CLI accepts arguments of the form `[NAMESPACE:]PATH`, with colons (`:`) separating the namespace from the path. In Windows a drive letter at the start of the path can be misinterpreted as a namespace.

cli/src/commands/mod.rs

@@ -114,10 +114,19 @@ fn meta_file_value_parser(
 ///
 /// Returns the namespace and the path. If the namespace is not provided
 /// returns [`None`].
+/// 
+/// In Windows, namespaces with a single character are not allowed as they can
+/// be confused with a drive letter.
 fn path_with_namespace_parser(
     input: &str,
 ) -> Result<(Option<String>, PathBuf), anyhow::Error> {
     if let Some((namespace, path)) = input.split_once(':') {
+        // In Windows a namespace with a single letter could actually be a 
+        // drive letter.
+        #[cfg(target_os = "windows")]
+        if namespace.len() == 1 {
+            return Ok((None, PathBuf::from(input)));
+        }
         Ok((Some(namespace.to_string()), PathBuf::from(path)))
     } else {
         Ok((None, PathBuf::from(input)))