Backport #2015

Cargo.lock

@@ -5228,6 +5228,7 @@ dependencies = [
  "pretty_assertions",
  "quote",
  "scale-info",
+ "scale-typegen",
  "scale-typegen-description",
  "scale-value",
  "serde",

cli/Cargo.toml

@@ -27,6 +27,7 @@ chain-spec-pruning = ["smoldot"]
 
 [dependencies]
 subxt-codegen = { workspace = true }
+scale-typegen = { workspace = true }
 subxt-utils-fetchmetadata = { workspace = true, features = ["url"] }
 subxt-metadata = { workspace = true }
 subxt = { workspace = true, features = ["default"] }

cli/src/commands/codegen.rs

@@ -210,8 +210,18 @@ fn codegen(
         codegen.no_docs()
     }
 
-    let metadata = subxt_metadata::Metadata::decode(&mut &*metadata_bytes)
-        .map_err(|e| eyre!("Cannot decode the provided metadata: {e}"))?;
+    let metadata = {
+        let mut metadata = subxt_metadata::Metadata::decode(&mut &*metadata_bytes)
+            .map_err(|e| eyre!("Cannot decode the provided metadata: {e}"))?;
+
+        // Run this first to ensure type paths are unique (which may result in 1,2,3 suffixes being added
+        // to type paths), so that when we validate derives/substitutions below, they are allowed for such
+        // types. See <https://github.com/paritytech/subxt/issues/2011>.
+        scale_typegen::utils::ensure_unique_type_paths(metadata.types_mut())
+            .expect("ensure_unique_type_paths should not fail; please report an issue.");
+
+        metadata
+    };
 
     // Configure derives:
     let global_derives = raw_derives

macro/src/lib.rs

@@ -102,7 +102,17 @@ fn subxt_inner(args: TokenStream, item_mod: syn::ItemMod) -> Result<TokenStream,
         .map_err(|e| TokenStream::from(e.write_errors()))?;
 
     // Fetch metadata first, because we need it to validate some of the chosen codegen options.
-    let metadata = fetch_metadata(&args)?;
+    let metadata = {
+        let mut metadata = fetch_metadata(&args)?;
+
+        // Run this first to ensure type paths are unique (which may result in 1,2,3 suffixes being added
+        // to type paths), so that when we validate derives/substitutions below, they are allowed for such
+        // types. See <https://github.com/paritytech/subxt/issues/2011>.
+        scale_typegen::utils::ensure_unique_type_paths(metadata.types_mut())
+            .expect("ensure_unique_type_paths should not fail; please report an issue.");
+
+        metadata
+    };
 
     let mut codegen = CodegenBuilder::new();
 
@@ -135,6 +145,7 @@ fn subxt_inner(args: TokenStream, item_mod: syn::ItemMod) -> Result<TokenStream,
             .into_iter()
             .collect(),
     );
+
     for d in args.derive_for_type {
         validate_type_path(&d.path.path, &metadata);
         codegen.add_derives_for_type(d.path, d.derive.into_iter(), d.recursive);