Issue #20152 has been updated by byroot (Jean Boussier).

Where will this be used?

I'm not sure I understand the question. This would be called in `extconf.rb` ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106025 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by kddnewton (Kevin Newton). Prism would use this as well: https://github.com/ruby/prism/blob/829ac0ed3f449313584aae35db98fd7614eb9d63/... ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106030 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by byroot (Jean Boussier).

Does skip_compilation just make a Makefile does nothing?

I don't know, I'm unfamiliar with the internals of `mkmf` and not well versed in all this tooling. I'm just requesting the capability of skipping compilation from `extconf.rb`, not prescribing an implementation nor a specific API. If you want a specific implementation plan, I can look into it. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106049 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by byroot (Jean Boussier).

This is not something mkmf can do on its own, it would need changes in RubyGems

Thanks for the info, as I said, I'm quite unfamiliar with how these pieces fit together.

Maybe RubyGems could recognize dummy Makefiles

Or look for a specially named file? This way `mkmf` could just create that file and move on?

OTOH, IMO it's not a big ask for devs/users to install make when they are installing gems.

On UNIX systems it's not, but on Windows it start to be a bit more complicated.

So trying to avoid needing make on JRuby seems very niche to me.

I honestly don't mind it that much, but it's true that if the end the Makefile does nothing, we might as well not require make, would be nicer. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106052 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by jeremyevans0 (Jeremy Evans). nobu (Nobuyoshi Nakada) wrote in #note-5:

byroot (Jean Boussier) wrote in #note-2:

...

This would be called in `extconf.rb`

Does `skip_compilation` just make a Makefile does nothing? Then it won't be able to fix the issue that `make` is needed, since `make` is called outside `extconf.rb`.

I agree that this isn't a `mkmf`/`extconf.rb` issue. This is a rubygems issue. I think the easiest way to fix this would be for rubygems to check for a `skip-compilation-RUBY_ENGINE` file in the same directory as `extconf.rb`. If it exists, do not run `extconf.rb` or `make`. If it exists after calling `extconf.rb`, do not call `make`. This fixes cases where an extension is not needed for a certain engine, as well as cases where an extension is not needed in certain configurations, such as when a pure-ruby implementation is also shipped in the same gem, and a native library necessary for the native extension is not available. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106056 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by byroot (Jean Boussier).

Another possibility would be if there is no Makefile created by extconf.rb, then RubyGems would not call make

I quite like that one. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106063 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by lloeki (Loic Nageleisen).

I agree that this isn't a mkmf/extconf.rb issue. This is a rubygems issue.

Sounds like so to me as well.

Maybe RubyGems could recognize dummy Makefiles

Not too fond of that.

...

Another possibility would be if there is no Makefile created by extconf.rb, then RubyGems would not call make

I quite like that one.

I too, sounds better than the one above.

Also one might need make anyway, e.g. for gems used via FFI like sassc and prism, where make is used to build the C code

Not necessarily, when platform specific binary gems are available (e.g mini_racer / libv8-node). The solutions we found in our case was: - dependent gem has a hard add_runtime_dependency on the dependency. This is a prerequisite of being able to specify the dependency version requirement at gem install/bundle install time. - provide binary gems, which then inform of feature availability at runtime (something like `MyNamespace.available?` returning `true`) - the `ruby` platform gem is either one of: - a shim, and provides no implementation whatsoever, thus `MyNamespace.available?` returns `false`, which is a bit of a lie since the `ruby` platform is actually not supported - sidestep rubygems platform resolution and attempt fetching binary for that binary platform at `gem install` time. if it succeeds `MyNamespace.available?` returns `true` and succeeds `MyNamespace.available?` returns `false`, which is sad as it breaks the common "install does network but does not execute" and "build executes but does not do network" expectation. - able to compile from C/Rust source, but limit to a set list of platforms in `extconf.rb` and otherwise produce a dummy Makefile - able to compile from C/Rust source, if compilation succeeds `MyNamespace.available?` will return `true` but if compilation fails the result is swallowed, a warning is printed, and `MyNamespace.available?` will return `false` This is all mandated by ruby gems being unable to declare optional dependencies in gemspecs: ``` s.add_runtime_dependency, foo, '~> 1.1', optional: true ``` Which would mean that if `foo` is present in the bundle it must be `['>= 1.1', '< 2.0.a']` but if it's not in GEM_HOME / in Gemfile / does not resolve that's okay, for which there are two sides to the coin: dependency is not installed at all or dependency failed to install. The only way to work around that is at runtime, well after dependency resolution / gem install time: - have the hard dependency as above, ignore compilation failure / have a ruby platform shim gem, and check for availability at runtime - not have the hard dependency, and hopefully do the optional gem version check at runtime, duplicating rubygems/bundler dependency resolution (badly) Note that I'm not positing the above as a solution, merely that it seems to me that it hints at the requirement on creating dummy Makefiles that do nothing might indeed be a deeper rubygems limitation moving a dependency resolution problem to be solved by either build time or runtime hacks. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106143 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by byroot (Jean Boussier). I tried implementing this idea in `rubygems` https://github.com/rubygems/rubygems/pull/7372. I still think it would be nice for `mkmf` to provide a `skip_compilation` helper that would generate the dummy makefile (for backward compatibility?) and create the skip file. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106146 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by byroot (Jean Boussier). I don't think it makes it useless. For now gems can do both (dummy makefile and `skip-build` file). And in a few years, as older versions become deprecated, we'll be able to only do the `skip-build`. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106154 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/

Issue #20152 has been updated by headius (Charles Nutter). Finally jumping in here. I think this was initiated by me filing an issue on erb to move the C extension out to a separate gem. Background: JRuby users traditionally have not needed any build tools **whatsoever** to install JRuby and build and run Rails applications. Everything is pre-built for JVM (though that has changed a bit with sassc). As it existed a few versions ago, the erb gem would unconditionally try to build the C extension it ships with, which meant that JRuby users could not install it. The first fix was to just emit a dummy Makefile on JRuby, which only half fixes it; JRuby users would still have to have `make` installed, even though the build would produce **nothing at all**. Let's be honest, the empty-Makefile trick is a hack at best. There should be a way in RubyGems to indicate that the current OS, OS version, ARCH, RUBY_ENGINE, RUBY_VERSION, etc does not need an extension built, so don't try to build it. That obviously applies in this case (Ruby fallback works fine), but it also applies to any gems that want to ship pre-built native libraries with more customization than just OS and ARCH. I don't have a strong opinion on "skip dummy makefiles" vs "don't try to build" but the former would integrate more easily. There *are* places where we accept that `make` will be needed, like sassc (to build the native library bound in Ruby using FFI), and we would not want to disable `make` for all gems. We just want to fix the ones that really don't need to build, like erb. ---------------------------------------- Feature #20152: mkmf / extconf: Add a proper way to not compile the extension https://bugs.ruby-lang.org/issues/20152#change-106415 * Author: byroot (Jean Boussier) * Status: Open * Priority: Normal ---------------------------------------- ### Context There are various gems that ship with a native extension as a way to speedup part of the gem, but also ship with a pure Ruby version of these methods as a fallback. So they only want to compile the extension if the platform supports it, and if not, just fallback to the slightly slower Ruby version. Right now users rely on one of two hacks to do this. Either they create an empty Makefile, but then still depend on `make` being available, or publish platform specific packages without any extension in them. Examples: - [`bootsnap` skip compilation if not on MRI or TruffleRuby](https://github.com/Shopify/bootsnap/blob/070151f1305f23102365d6b4476a91c02de...) - [`erb` has an extension for MRI but then need to publish a `java` version of the gem that doesn't actually contain Java code, just to skip compilation on JRuby](https://github.com/ruby/erb/issues/52) - [`hiredis-client` skips the compilation for Windows and non-MRI rubies](https://github.com/redis-rb/redis-client/blob/1ab081c1d0e47df5d55e011c9390c7...) ### Feature It would be very useful to have some proper first class API to skip compiling the extension. Something like: ```ruby require "mkmf" if RUBY_ENGINE != "ruby" || RUBY_PLATFORM.match?(/mswin/) skip_compilation else # ... end ``` cc @k0kubun @headius -- https://bugs.ruby-lang.org/