Fails to compile on WebGL platform contain native plugin files (.bc)

I created a simple native plugin for Unity 2021.2.0b2 with emscripten 2.0.19.

emcc Main.cpp -emit-llvm -c -o NativePluginExample.bc

Main.cpp

Code (CSharp):

1. #if defined(__CYGWIN32__)
2.     #define UNITY_INTERFACE_API __stdcall
3.     #define UNITY_INTERFACE_EXPORT __declspec(dllexport)
4. #elif defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(_WIN64) || defined(WINAPI_FAMILY)
5.     #define UNITY_INTERFACE_API __stdcall
6.     #define UNITY_INTERFACE_EXPORT __declspec(dllexport)
7. #elif defined(__MACH__) || defined(__ANDROID__) || defined(__linux__)
8.     #define UNITY_INTERFACE_API
9.     #define UNITY_INTERFACE_EXPORT
10. #else
11.     #define UNITY_INTERFACE_API
12.     #define UNITY_INTERFACE_EXPORT
13. #endif
14.  
15. extern "C"
16. {
17.  
18. UNITY_INTERFACE_EXPORT int UNITY_INTERFACE_API GetNumber()
19. {
20.     return 123;
21. }
22.  
23. }
24.  

NativePluginExample.cs

Code (CSharp):

1. using UnityEngine;
2. using System.Runtime.InteropServices;
3.  
4. namespace NativePluginExample
5. {
6.  
7.     public class NativePluginExample : MonoBehaviour
8.     {
9.  
10. #if (UNITY_IOS || UNITY_TVOS || UNITY_WEBGL) && !UNITY_EDITOR
11.         [DllImport ("__Internal")]
12. #else
13.         [DllImport("NativePluginExample")]
14. #endif
15.         public static extern int GetNumber();
16.  
17.         void Start()
18.         {
19.             Debug.Log(GetNumber());
20.         }
21.     }
22.  
23. }

I imported the generated NativePluginExample.bc into new project ( Unity2021.2.0b2 ) and tried to build it. However, the following error occurs during compilation. ( NativePluginExample.unitypackage )

Code (CSharp):

1. Building Library/Bee/artifacts/WebGL/build/debug_WebGL_wasm/build.js failed with output:
2. emcc:WARNING: --llvm-lto ignored when using llvm backend
3. emcc2: warning: EXTRA_EXPORTED_RUNTIME_METHODS is deprecated, please use EXPORTED_RUNTIME_METHODS instead [-Wdeprecated]
4. emcc2: error: /var/folders/l3/v_86snz551j_cjtcwbd_chb80000gn/T/tmpzxgicvcyNativePluginExample.a: File has a suffix of a static library ('.a',), but instead is an LLVM bitcode file! When linking LLVM bitcode files use .bc or .o.
5. UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&) (at /Users/bokken/buildslave/unity/build/Modules/IMGUI/GUIUtility.cs:189)
6.  

When using emscripten1.38.11 and Unity2019.4.18f1, it works fine.

 

This seemed to work up until 2021.2.0a19 but stopped working in 2.0b1 , 2.0b2 and 2.0b3 .
Unfortunately the prior version 2021.1 didn't have the recent changes to the WebGL video-permissions so in order for our apps to work on Safari, we needed to use 2021.2 (as discussed with @jukka_j ).

Now, with 2.0b1 no longer building the native plugin files above, we're kind of stuck. Please help @Unity-Team!

 

Tried again with 2021.2.0b4, still not working.

Did you file a bug report yet @EnoxSoftware ? (via the built-in editor tool in Unity? I usually got good feedback on those)

 

Yesterday, I submitted a bug report via UnityEditor.