Go packages

If you want to package a Go package to conda-forge, you can use this recipe template:

context:
  version: "0.1.0"

package:
  name: example-package
  version: ${{ version }}

source:
  url: https://github.com/example-package/example-package/archive/refs/tags/v${{ version }}.tar.gz
  sha256: 0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef
  target_directory: src

build:
  number: 0
  script:
    - cd src
    - go-licenses save . --save_path ../library_licenses
    - if: unix
      then: go build -v -o $PREFIX/bin/example-package -ldflags="-s -w"
      else: go build -v -o %LIBRARY_BIN%\example-package.exe -ldflags="-s"
    - if: unix
      then:
        - mkdir -p $PREFIX/share/zsh/site-functions $PREFIX/share/bash-completion/completions $PREFIX/share/fish/vendor_completions.d
        - $PREFIX/bin/example-package completion --shell zsh > $PREFIX/share/zsh/site-functions/_example-package
        - $PREFIX/bin/example-package completion --shell bash > $PREFIX/share/bash-completion/completions/example-package
        - $PREFIX/bin/example-package completion --shell fish > $PREFIX/share/fish/vendor_completions.d/example-package.fish

requirements:
  build:
    - ${{ compiler("go-nocgo") }}
    - go-licenses

tests:
  - script: example-package -help
  - package_contents:
      bin:
        - example-package
      files:
        - if: unix
          then:
            - share/bash-completion/completions/example-package
            - share/fish/vendor_completions.d/example-package.fish
            - share/zsh/site-functions/_example-package
      strict: true

about:
  homepage: https://github.com/example-package/example-package
  summary: Summary of the package.
  description: |
    Description of the package
  license: MIT
  license_file:
    - src/LICENSE
    - library_licenses/
  documentation: https://pkg.go.dev/github.com/example-package/example-package
  repository: https://github.com/example-package/example-package

extra:
  recipe-maintainers:
    - LandoCalrissian

This recipe template supports different features:

• Package licenses of statically linked libraries.
• Generate shell completions for bash, zsh, and fish on Unix platforms. This assumes the binary supports a completion --shell <shell> subcommand. The completion files are installed to the standard locations under $PREFIX/share/. If your tool does not support generating completions, you can remove those build and test lines.
• Verify that both the binary and the shell completion files are present using package_contents tests, with strict: true to ensure no unexpected files are installed.

If your package requires cgo instead of go-nocgo, you can use ${{ compiler("go-cgo") }} instead to build the package. By default, the go-nocgo compiler is used. Using ${{ compiler("go-cgo")) }} also requires ${{ compiler("c") }} and ${{ stdlib("c") }} and may require ${{ compiler("cxx") }} if C++ code is compiled. C/C++ build tools such as make, autoconf, automake, libtool or cmake may also be needed.

Sometimes, go-licenses might fail to detect licenses for some packages. In such cases, you can manually download the license file from the official source and add --ignore github.com/bad-package/bad-package to the go-licenses invokation. See here for an example.

Some packages ship multiple binaries, in which case the go build command needs to be run separately for each binary. It is increasingly common for the go build command to require specifying a subdirectory, in which case the build steps would be slightly modified as shown below:

go-licenses save ./cmd/example-package --save-path ../library_licenses
go build -v -o ${PREFIX}/bin/example-package -ldflags="-s -w" ./cmd/example-package

Some older Go packages that are not using Go modules yet can be converted by using:

go mod init
go mod tidy

Additional steps maybe required depending on which Go dependency manager the project has been using.

Until native macOS Arm runners are the default for conda-forge, you might need to set the following in conda-forge.yml to ensure that the $PREFIX/bin/example-package completion --shell ... steps work:

provider:
  osx_arm64: azure

Generating the completions only works when running the native binary which doesn't work with osx-64 -> osx-arm64 cross-compilation.