Fix #143 - Childprocess v1.0.0 failing to install.

[farkasmate]

No description provided.

[coveralls]

Coverage remained the same at 94.688% when pulling d84a702 on farkasmate:rake_runtime_dependency into f006e08 on enkessler:master.

[sds]

Thanks for the fix, @farkasmate. Given your comment in the issue this seems like the correct way forward.

One additional clarification (not specifically directed at you): any reason we need to limit rake to < 12?

[enkessler]

The limit is there so that we don't get bitten by a major version bump from rake and 11.x is what was released at the time that the limit was added. We can probably knock it up to < 13.0 and see if CI is still happy.

[yaauie]

Yes, this eliminates the situation where installation is broken when rake is missing.

But it also propagates rake as a runtime dependency of any app that includes childprocess and returns any app that uses childprocess on any platform to a state where rake is always available at runtime. For users who are concerned about the surface area of their applications for security or performance reasons, this is less than desirable.

Since we have a known workaround (pin to 0.9.x), I advocate for taking the time to find a solution that doesn't add runtime dependencies that aren't actually necessary at runtime, or at least reduces the effect to platforms on which they are needed for the installation.

[enkessler]

The change came from a desire to not have ffi be a dependency. So...it's kind of a 'pick your poison' situation. Between the two, I'd guess that more places are fine having rake installed than ffi. If there is yet another solution that doesn't require either gem as a mandatory dependency, then that would be even better.

[farkasmate]

@enkessler If a conditional dependency (ffi on Windows) is all you want, you can remove ext/mkrf_conf.rb and do a conditional instead in childprocess.gemspec:

-  s.extensions = 'ext/mkrf_conf.rb'
+  s.add_runtime_dependency 'ffi', '~> 1.0', '>= 1.0.11' if Gem.win_platform?

With this you don't need rake at runtime. As you pointed out, that generated Rakefile has no use at the moment.

What do you think?

[yaauie]

@farkasmate conditionals in the gemspec don't quite work in this case, because they are evaluated at gem build, before the gem is uploaded to rubygems.

[farkasmate]

Ah, OK.

[sds]

I've looked at alternative extensions we could implement, but the introduction of rake as a dependency is the only way to do this in a platform-agnostic way. Other extensions require the existence of make or other tools, which may not be installed on some systems.

For this reason, and given the fact that rake is usually (but not always) installed by default on Ruby systems, it seems reasonable to add a dependency on rake for sake of removing the ffi dependency for all non-Windows systems.

[sds]

Followed up with a PR to relax the rake constraint in #147.

[sds]

Following up here to say we've removed the magic ffi install logic in #160, allowing us to remove the runtime dependency on rake. This dependency removal will ship in ChildProcess 3.0.0.