MoonBit Test Toolchain

This directory contains a test toolchain for MoonBit that can be used for development and testing when the real MoonBit compiler is not available.

Usage

Option 1: Using the Test Toolchain (Recommended for Development)

1. Create the test toolchain (already done):

   bazel run //:test_toolchain.sh

2. Update your WORKSPACE file to use the local toolchain:

   # In your WORKSPACE file:
   local_repository(
       name = "moonbit_toolchain",
       path = "moonbit_toolchain",
   )
   
   register_toolchains("@moonbit_toolchain//:moonbit_toolchain")

3. Build your project:

   bazel build //your/target:here

Option 2: Using the Hermetic Toolchain (When Available)

When the real MoonBit compiler becomes available:

1. Update the checksum registry with correct URLs and checksums:

   • Edit moonbit/checksums/moonbit.json
   • Add the correct SHA256 checksums for each platform
   • Verify the download URLs are correct

2. Use the hermetic toolchain in WORKSPACE:

   load("//moonbit/tools:hermetic_toolchain.bzl", "moonbit_toolchain_repository")
   
   moonbit_toolchain_repository(
       name = "moonbit_toolchain",
       version = "0.6.33",  # or your desired version
   )
   
   register_toolchains("@moonbit_toolchain//:moonbit_toolchain")

Option 3: Using a Local MoonBit Installation

If you have MoonBit installed locally:

1. Create a custom toolchain BUILD file:

   # In a custom BUILD file:
   exports_files(["path/to/your/moon"])
   
   filegroup(
       name = "moonbit_toolchain",
       srcs = ["path/to/your/moon"],
   )

2. Register your custom toolchain:

   local_repository(
       name = "custom_moonbit_toolchain",
       path = "path/to/your/build/file",
   )
   
   register_toolchains("@custom_moonbit_toolchain//:moonbit_toolchain")

Toolchain Contents

• moon - Placeholder MoonBit compiler executable
• BUILD.bazel - Bazel build file defining the toolchain
• WORKSPACE - WORKSPACE file for the toolchain
• README.md - This file

Troubleshooting

"MoonBit compiler not found" Errors

If you see errors about the MoonBit compiler not being found:

1. Check your toolchain registration in WORKSPACE
2. Verify the repository exists with bazel query @moonbit_toolchain//...
3. Ensure the toolchain is registered with bazel query @moonbit_toolchain//:moonbit_toolchain

Download Failures

If the hermetic toolchain fails to download:

1. Check your internet connectivity
2. Verify the MoonBit release exists at the specified URL
3. Check GitHub rate limits (you may be rate-limited)
4. Use the test toolchain as a fallback

Platform Not Supported

If your platform is not supported:

1. Check the supported platforms in moonbit/checksums/moonbit.json
2. Add your platform to the checksum registry if it should be supported
3. Use the test toolchain for development
4. Consider contributing platform support to the project

Development Notes

The test toolchain creates dummy output files that simulate MoonBit compilation. This allows you to:

• Test the build system without the real compiler
• Develop rules and build logic
• Verify toolchain resolution works
• Test cross-platform builds

When the real MoonBit compiler becomes available, simply switch to the hermetic toolchain or local installation method.

Contributing

If you want to help improve the MoonBit toolchain:

1. Update checksums when new MoonBit versions are released
2. Add support for new platforms as they become available
3. Improve error handling and user experience
4. Add more comprehensive tests
5. Document best practices for MoonBit development

License

This test toolchain is provided under the Apache License 2.0, same as the main rules_moonbit project.