This repo contains scripts to build binaries locally and on GitHub Actions.

Navigate to GithHub actions. Select the workflow "Build and upload Ruby runtime" then click the drop down "Run workflow" and enter the desired Ruby version. This will trigger a build for all supported stacks. If a version is not supported on a specific stack, add that logic to the build.rb file and to the GitHub action yaml logic.

Employees of Heroku see: The Ruby language guides (not public) for additional details on building and deploying Ruby versions.

Logic lives in the build.rb script at the root of this project. It will call ./configure and make with the corresponding inputs. This file is coppied into a docker image when $ bundle exec rake "generate_image[heroku-22]" is called. See dockerfiles/Dockerfile.heroku-22 for an example.

You can see the rake code:

desc "Build docker image for stack"
task :generate_image, [:stack] do |t, args|
  require 'fileutils'
  FileUtils.cp("dockerfiles/Dockerfile.#{args[:stack]}", "Dockerfile")
  system("docker build -t hone/ruby-builder:#{args[:stack]} .")
  FileUtils.rm("Dockerfile")
end

Once built it can be invoked with different inputs like:

$ export OUTPUT_DIR="./builds"
$ export CACHE_DIR="./cache"
$ docker run -v $OUTPUT_DIR:/tmp/output -v $CACHE_DIR:/tmp/cache -e VERSION=3.2.2  -e STACK=heroku-22 hone/ruby-builder:heroku-22

This generates a file in the builds directory with the given binary. From there it can be uploaded to S3 so customers of the heroku/ruby buildpack can download the pre-built binary and put it on the PATH.

I'm assuming you've already setup Docker.

The directory layout used by this script inside the docker container is as follows:

• It builds the binary as tarball and puts it in /tmp/output.
• All the work is performed in a clean room /tmp/workspace.
• The artifacts downloaded for the build are put into /tmp/cache.
• Finally, the /app directory is there like in a normal cedarish app, so we'll prefix things within this directory so the load paths are useable and fast lookups when using the --enable-load-relative flag. We'll need special build rubies for ruby 1.9.2/1.8.7 since --enable-load-relative is broken there.

This build tool supports heroku's multiple stacks. The built rubies will go in the builds/ directory. We also have a rubies/ directory for ensuring consistent builds. In each of these directories, they're split into a stack folder. All of the heroku-22 builds will be in builds/heroku-22/ for instance.

First we'll need to generate the docker images needed for building the appropriate stack.

$ bundle exec rake "generate_image[heroku-22]"

Generate a ruby build script:

$ bundle exec rake "new[3.1.3,heroku-22]"

From here, we can now execute a ruby build:

$ bash rubies/heroku-22/ruby-3.1.3.sh

When it's complete you should now see builds/heroku-22/ruby-3.1.3.tgz.

If you set the env vars AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY, you can upload them to s3. By default, we upload to the heroku-buildpack-ruby s3 bucket.

$ bundle exec rake upload[3.1.3,heroku-22]

Sometimes a version might need to be tested, for example a commit on Ruby trunk.

If you're building from a specific commit, then fork ruby/ruby to your own repo.

To build it first generate a new file:

bundle exec rake new[2.6.0,heroku-18]

Then add in the destination to the GIT_URL:

docker run -v $OUTPUT_DIR:/tmp/output -v $CACHE_DIR:/tmp/cache -e VERSION=2.6.0 -e GIT_URL=https://github.com/schneems/ruby#schneems/bundler -e STACK=heroku-18 hone/ruby-builder:heroku-18

If you need to use a branch you can put it in the url after the #.

To configure the build, we use environment variables. All of them are listed below:

• VERSION - This is the ruby version being used. It's expected to be in the format: "#{MAJOR}.#{MINOR}.#{TEENY}-p#{PATCH}". This option is required.
• BUILD - If this flag is set (can be set to anything for true), then hammer-ruby will build a "build" ruby. This sets the prefix to "/tmp/ruby-#{MAJOR}.#{MINOR}.#{TEENY}". This is required for ruby 1.8.7 and 1.9.2 since the --enable-load-relative flag does not work properly. --enable-load-relative allows a ruby to be executed from anywhere and not just the prefix directory. By required, you need to build two binaries: one where BUILD is false (runtime ruby) and where BUILD is true (build ruby).
• DEBUG - If this flag is set (can be set to anything for true), then hammer-ruby will set debug flags in the binary ruby being built.
• RUBYGEMS_VERSION - This allows one to specify the Rubygems version being used. This is only required for Ruby 1.8.7 since it doesn't bundle Rubygems with it.
• GIT_URL - If this option is used, it will override fetching a source tarball from http://ftp.ruby-lang.org/pub/ruby with a git repo. This allows building ruby forks or trunk. This option also supports passing a treeish git object in the URL with the # character. For instance, git://github.com/hone/ruby.git#ruby_1_8_7.
• S3_BUCKET_NAME - This option is the S3 bucket name containing of dependencies for building ruby. If this option is not specified, hammer-ruby defaults to "heroku-buildpack-ruby". The dependencies needed are libyaml-0.1.4.tgz and libffi-3.0.10.tgz.
• JOBS - the number of jobs to run in parallel when running make: make -j<jobs>. By default this is 2.