2014/07/20

Oops - gauche-package regression

Alert for those who start writing new extention package with Gauche 0.9.4. When you create the skeleton files by gauche-package generate, you need to tweak the generated files to make them work.

Before going into details, I just describe what to do:

After generating skeleton files, edit configure script to add the following stuff right after ;; Output line:

(use gauche.package)
(let1 gpd-file #"~(cf$ 'PACKAGE_NAME).gpd"
  (with-output-to-file gpd-file
    (cut write-gauche-package-description
      (make <gauche-package-description>
        :name (cf$ 'PACKAGE_NAME)
        :version (cf$ 'PACKAGE_VERSION)
        :configure (string-join (command-line))))))

And in Makefile.in, remove configure from the rule of maintainer-clean target, as shown in this patch.

  maintainer-clean : clean
-       rm -rf $(CONFIG_GENERATED) configure VERSION
+       rm -rf $(CONFIG_GENERATED) VERSION

Now, the explanation.

0.9.4 is shipped with new gauche.configure module, which attempts to replace autoconf-based configuration to build Gauche extensions.

Autoconf is well-built system, but it makes great effort to make configure scripts work on a minimal environment. In order to do so, it requires an extra step for developers to generate configure script from configure.ac etc. It is reasonable for distributing basic tools to the destination platform that lacks them.

However, when installing Gauche extensions, we know for sure that the destination platform already have Gauche installed, so the configure script doesn't need to be restricted in the minimal shell features. In fact, we can write configure script itself as a Gauche script, eliminating the step for developers to generate configure script from other files.

Nowadays more and more projects don't bother to create distribution tarballs and ask users to just pull from repository. Making configure script a source, not something to be generated, has advantage for not requiring users to run autoconf.

So I migrated the default skeleton files to use new configure features. But I forgot to cover a couple of points, as shown above.

The .gpd file is to keep metadata of the extension package. In the old skeleton configure.ac file, it is generated by calling gauche-package make-gpd. My plan is to provide an easier API in gauche.configure, which will be in the next version of Gauche.

And of course, we no longer need to remove configure in maintainer-clean!

Autoconf has comprehensive feature tests gauche.configure can't match. If you need advanced feature tests, you may still want to use autoconf-based configuration. Just give --autoconf option to gauche-package generate, and it gives you configure.ac.

gauche-package generate --autoconf YOUR-PACKAGE-NAME

Tags: 0.9.4, Extension, gauche-package