chore(vendor): add anyhow crate

third_party/crates/clap_derive-4.6.7/src/utils/error.rs

@@ -0,0 +1,22 @@
+pub(crate) trait SpanError {
+    #[allow(non_snake_case)]
+    fn EXPECTED_Span_OR_ToTokens<D: std::fmt::Display>(&self, msg: D) -> syn::Error;
+}
+
+pub(crate) trait ToTokensError {
+    #[allow(non_snake_case)]
+    fn EXPECTED_Span_OR_ToTokens<D: std::fmt::Display>(&self, msg: D) -> syn::Error;
+}
+
+impl<T: quote::ToTokens> ToTokensError for T {
+    fn EXPECTED_Span_OR_ToTokens<D: std::fmt::Display>(&self, msg: D) -> syn::Error {
+        // Curb monomorphization from generating too many identical `new_spanned`.
+        syn::Error::new_spanned(self.to_token_stream(), msg)
+    }
+}
+
+impl SpanError for proc_macro2::Span {
+    fn EXPECTED_Span_OR_ToTokens<D: std::fmt::Display>(&self, msg: D) -> syn::Error {
+        syn::Error::new(*self, msg)
+    }
+}