This post originated from an RSS feed registered with Ruby Buzz by Eric Hodel. Original Post: Packaging from a gemspec is not the Best Way Feed Title: Segment7 Feed URL: http://blog.segment7.net/articles.rss Feed Description: Posts about and around Ruby, MetaRuby, ruby2c, ZenTest and work at The Robot Co-op. Latest Ruby Buzz Posts Latest Ruby Buzz Posts by Eric Hodel Latest Posts From Segment7

Or, why you should use Hoe (or a tool like it) to package your gems.

A while back Yehuda wrote Using .gemspecs as Intended and asserted that packaging directly from a .gemspec file was both the way you were supposed to build gems and the best way to build gems.

This is not true.

Rake::GemPackageTask (now Gem::PackageTask) was added to rake less than two weeks after the first commit on RubyGems. Which points to the recognition of a need to have a better way to describe and build a gem than just a file.

Using rake allows you to do more than just package a static list of files in a clean and reusable manner. You can write tasks to generate files that are then packaged in your gem at build time. Hoe builds atop Rake to support many types of generated files easily through task dependencies.

For example, generating a .gemtest file to work with GemTesters, integrating with rake-compiler for pre-compiled gems or generating parsers.

I can hear you thinking "you might have a point there, but I don't generate any files, so how does this apply to me?" Well, what if you wanted to include generated man pages in your gem using binman?

In the world of packaging directly from a gemspec the way to automatically generate files is to violate RubyGems' internals by overriding Gem::Specification#initialize. I can't blame Suraj Kurapati for this, he's working within the framework of the popular thing to do and this is the only way he could implement it.

(Hoe, on the other hand, handles such pre-package dependencies through a set of pre-defined rake tasks that you can add dependencies too. If you need to generate a file you make the package task dependent on it. See the examples above.)

How can we make this better?

First of all, stop using gemspecs as the One True Description of your gem. Let rake generate it. While Hoe is obviously the best way to do this, it doesn't support generating the gemspec by default. You can use one of the gemspec plugins for that. I'm sure there are other build tools have the equivalent built right in.

Second, if you've writing a tool that generates files that will be packaged into a gem, provide a rake task like the one that ships with binman that build tool authors can hook to make packaging seamless.

(Also, please, don't use system when you can use API.)