set required_rubygems_version for native gems that specify the linux libc

[flavorjones]

Problem I'm trying to solve

Rubygems does not correctly recognize -musl or -gnu platform suffixes until v3.3.22.

Solution

If rake-compiler is building a linux native gem that specifies a libc in its platform object, then add ">= 3.3.22" to the required_rubygems_version requirement.

https://github.com/rubygems/rubygems/blob/master/CHANGELOG.md#3322--2022-09-07

Context

While working on musl support in the precompilation toolchain:

• first-class support for musl platforms rake-compiler-dock#111
• precompiled: add first-class linux-musl support flavorjones/ruby-c-extensions-explained#27
• introduce general musl support sparklemotion/sqlite3-ruby#442
• feat: first-class musl support sparklemotion/nokogiri#3111

I noticed that Ruby 3.0 is still shipping with Rubygems 3.2.33, which does not recognize these gem platforms.

Specifying the rubygems requirement changes the error experienced by users during gem installation from:

ERROR: While executing gem ... (Gem::Exception)
Unable to find spec for #<Gem::NameTuple rcee_precompiled, 0.6.test.2024.0128.1724, aarch64-linux>

to:

ERROR: Error installing rcee_precompiled-0.6.test.2024.0128.1735-x86_64-linux-musl.gem:
rcee_precompiled-0.6.test.2024.0128.1735-x86_64-linux-musl requires RubyGems version >= 3.3.22.
The current RubyGems version is 3.2.33. Try 'gem update --system' to update RubyGems itself.

/cc @deivid-rodriguez @segiddins

[kou]

Can we simplify this?

Suggested change

	spec.required_rubygems_version = Gem::Requirement.new(gem_spec.required_rubygems_version)
	spec.required_rubygems_version.concat([">= 3.3.22"])
	spec.required_rubygems_version = spec.required_rubygems_version.requirements + [">= 3.3.22"]

[flavorjones]

Gem::Requirements does not support the #+ method. See https://docs.ruby-lang.org/en//3.2/Gem/Requirement.html for supported methods. This is the simplest form I can think of.

[kou]

I think that spec.required_rubygems_version.requirements is an Array not a Gem::Requirements.

[flavorjones]

I've changed this to

spec.required_rubygems_version = Gem::Requirement.new(gem_spec.required_rubygems_version, ">= 3.3.22")

@kou What you suggest doesn't work. requirements is an array, but Gem::Specification#required_rubygems_version= does not accept it as an argument:

spec = Gem::Specification.new do |s|
  s.name = 'my_gem'
  s.platform = Gem::Platform::RUBY
  s.extensions = ['ext/somegem/extconf.rb']
  s.required_rubygems_version = "!= 1.0.0"
end

spec.required_rubygems_version.requirements + [">= 3.3.22"]
# => [["!=", Gem::Version.new("1.0.0")], ">= 3.3.22"]

spec.required_rubygems_version = spec.required_rubygems_version.requirements + [">= 3.3.22"]
# /home/flavorjones/.rbenv/versions/3.2.3/lib/ruby/3.2.0/rubygems/requirement.rb:107:in `parse': Illformed requirement ["!="] (Gem::Requirement::BadRequirementError)
# 
#       raise BadRequirementError, "Illformed requirement [#{obj.inspect}]"
#             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
# 	from /home/flavorjones/.rbenv/versions/3.2.3/lib/ruby/3.2.0/rubygems/requirement.rb:139:in `block in initialize'
# 	from /home/flavorjones/.rbenv/versions/3.2.3/lib/ruby/3.2.0/rubygems/requirement.rb:139:in `map!'
# 	from /home/flavorjones/.rbenv/versions/3.2.3/lib/ruby/3.2.0/rubygems/requirement.rb:139:in `initialize'
# 	from /home/flavorjones/.rbenv/versions/3.2.3/lib/ruby/3.2.0/rubygems/requirement.rb:64:in `new'
# 	from /home/flavorjones/.rbenv/versions/3.2.3/lib/ruby/3.2.0/rubygems/requirement.rb:64:in `create'
# 	from /home/flavorjones/.rbenv/versions/3.2.3/lib/ruby/3.2.0/rubygems/specification.rb:702:in `required_rubygems_version='
# 	from /home/flavorjones/bar.rb:15:in `<main>'

[flavorjones]

I think that Gem::Requirement could be improved in two ways that would make this feature simpler to implement:

1. #dup should make a deep copy of @requirements. It does not, and so I am calling Gem::Requirement.new(gem_spec.required_rubygems_version) to duplicate it.
2. #concat could return self. It does not, and so I am doing this across two statements.

If those things were fixed, this could become

spec.required_rubygems_version = spec.required_rubygems_version.dup.concat(">= 3.3.22")

[kou]

Oh. I see.

[deivid-rodriguez]

👍

[kou]

Thanks!

[flavorjones]

See rubygems/rubygems#7439 which proposes changing Gem::Requirement and Gem::Specification to deep-copy requirements.