Replace nerves_toolchain_ctng dependency with template-based code embedding

[Copilot]

Toolchain packages had ~90% duplicate code across mix.exs files. External nerves_toolchain_ctng dependency caused version conflicts.

Changes

• Template system (template/)

  • EEx templates for mix.exs and README.md
  • Embedded copy of nerves_toolchain_ctng code (lib, scripts, patches, build.sh, defaults)

• Elixir-based generation

  • generate_toolchains.exs - Elixir script with embedded configuration for all 12 toolchains
  • Uses EEx for proper template processing
  • Module names automatically derived from target_tuple (no manual specification needed)
  • Makefile - make generate regenerates all packages

• Configuration structure (configs/)

  • Per-toolchain essential files stored in configs/<toolchain>/ directories
  • Contains defconfig, VERSION, LICENSE, and mingw32_x86_64_defconfig (where applicable)
  • Toolchain package directories are fully generated and excluded from repository

• Updated toolchain packages

  • Removed {:nerves_toolchain_ctng, path: "../nerves_toolchain_ctng"} dependency
  • All toolchain directories removed from repository (generated on-demand)
  • Added toolchain directories to root .gitignore
  • No .gitignore or mix.lock files in generated packages
  • Standardized description format (hyphens vs underscores)

Template structure

defmodule <%= @module_name %>.MixProject do
  defp deps do
    [{:nerves, "<%= @nerves_version %>", runtime: false}]
  end
  
  defp package_files do
    ["lib", "patches", "scripts", "build.sh", "defaults",
     <%= @package_files_list %>]
  end
end

Repository structure

• template/ - EEx templates and embedded nerves_toolchain_ctng code
• configs/ - Per-toolchain essential files (defconfig, VERSION, LICENSE)
• generate_toolchains.exs - Generator with configuration
• Toolchain directories created by running make generate

Each toolchain now self-contained. All generated code is created locally via make generate and excluded from the repository. Update shared code by modifying template/ and running make generate.

Original prompt

The toolchains packages all have a ton of duplication. Also it has turned out that keeping shared code in nerves_toolchain_ctng causes dependency versioning conflicts. Prototype a template toolchain package that takes a toolchain configuration and expands into a toolchain library with the nerves_toolchain_ctng code inside of it. Create a top level Makefile that instantiates all existing toolchains.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[fhunleth]

@copilot This is good. Please use Elixir instead of Python especially so that EEx can be used to process the .eex files. Also remove the generated code from the repository.

[Copilot]

@copilot This is good. Please use Elixir instead of Python especially so that EEx can be used to process the .eex files. Also remove the generated code from the repository.

Done! Replaced Python with Elixir (generate_toolchains.exs) using EEx for template processing, and removed all generated code from the repository. Users now run make generate to create the embedded files locally. See commit 27ceef8.

[fhunleth]

@copilot Remove :module_name and create it from the target_tuple. I don't see the defconfig settings for each target. I think that was deleted.

Also remove all of the toolchain directories. There's no need for storing the .gitignore files. Don't generate mix.lock files either.

[Copilot]

Done! Changes in commit d0f7193:

• Removed :module_name from config - now auto-generated from target_tuple via target_tuple_to_module_name/1
• Moved defconfig files (and VERSION, LICENSE) to configs/ directory - they weren't deleted
• Removed all toolchain directories from repository
• Added toolchain directories to root .gitignore
• Generator no longer creates mix.lock files
• No .gitignore files in generated packages