Archive:PackagingDrafts/RubyGem with C code

From FedoraProject

Jump to: navigation, search

Contents

Proposal for package Ruby Gem including extension library written in C

Current status

Current packaging guidelines on Fedora about Ruby Gems are mainly written on https://fedoraproject.org/wiki/Packaging/Ruby#Ruby_Gems

The guideline says: 

The install should be performed with the command
$ gem install --local --install-dir %{buildroot}%{gemdir} --force %{SOURCE0}

Problem

This causes some problems especially when Ruby Gem contains extension libraries written in C because of the following reason.

A-1

First of all the above procedure will cause the error like following. 

+ /usr/lib/rpm/check-buildroot
Binary file /home/tasaka1/rpmbuild/INSTROOT/rubygem-zoom-0.4.1-4.fc9p-root-tasaka1/usr/lib/debug/usr/lib/ruby/site_ruby/1.8/i386-linux/zoom.so.debug matches
Found '/home/tasaka1/rpmbuild/INSTROOT/rubygem-zoom-0.4.1-4.fc9p-root-tasaka1' in installed files; aborting
error: Bad exit status from /home/tasaka1/rpmbuild/INSTROOT/rpm-tmp.84251 (%install)

This is because with above command:

So the rebuilt C library may contain %{buildroot} string.

A-2

So to avoid this error some maintainers on Fedora of rubygems including extension written in C simply strip compiled C libraries before %install stage ends.

Solution to A

The problem written in A can be resolved when Ruby Gems are installed under %{_builddir} first.

B

Currently there is no mention about how to pass Fedora specific compilation flags correctly.

Solution to B

Usually ruby extension uses ruby script file named extconf.rb which has require 'mkmf'. mkmf.rb module accepts CONFIGURE_ARGS environment to specify CFLAGS so using this is preferred.

which usually contain require mkmf. In such case 

export CONFIGURE_ARGS="--with-cflags='%{optflags}'"

can be used, too. So using this method is preferred even for non-Gem packages.

Proposition

For packages which create C shared libraries using extconf.rb 

export CONFIGURE_ARGS="--with-cflags='%{optflags}'"

should be used to pass CFLAGS to Makefile correctly. This also applies to Ruby Gems.


Ruby Gem with extension libraries written in C

When Ruby Gem contains extension libraries written in C,

Revised proposition

From the comments I received, it seems that the following proposition is clearer.

(The part CONFIGURE_ARGS=... stays unchanged)

Ruby Gem with extension libraries written in C

When Ruby Gem contains extension libraries written in C,

Note

The current guideline 

If the Gem contains binary content (e.g., for a database driver), it must be marked 
as architecture specific, and all architecture specific content must be moved 
from the %{gemdir} to the [#ruby_sitearch %{ruby_sitearch} directory] during %install

must still apply.

Example 

%prep
%setup -q -T -c

%build
mkdir -p ./%{gemdir}
export CONFIGURE_ARGS="--with-cflags='%{optflags}'"
gem install --local --install-dir ./%{gemdir} -V --force %{SOURCE0}

%install
rm -rf %{buildroot}
mkdir -p %{buildroot}%{gemdir}
cp -a ./%{gemdir}/* %{buildroot}%{gemdir}

mkdir -p %{buildroot}%{ruby_sitearch}
mv %{buildroot}%{geminstdir}/lib/*.so %{buildroot}%{ruby_sitearch}
rm -rf %{buildroot}%{geminstdir}/ext

%clean
rm -rf %{buildroot}

%files
%defattr(-,root,root,-)
%{ruby_sitearch}/*.so
%{geminstdir}/
%{gemdir}/cache/%{gemname}-%{version}.gem
%{gemdir}/specifications/%{gemname}-%{version}.gemspec

Issues

[SOLVED] Installed C codes

Currently all C codes (in Gem file) are also installed with gem install (usually under %{geminstdir}/ext). In my recognition these files are used only for creating C libraries and are not needed anymore. So actually some packagers simply remove these files.

However Gem has its own metadata and Gem actually reports that these files should have been installed.

How should we treat these files?

[SOLVED] To pass CFLAGS correctly

I noticed that even for non-Gem Ruby packages, many packages containing C shared libraries

which usually contain require mkmf. In such case 

export CONFIGURE_ARGS="--with-cflags='%{optflags}'"

can be used.

So, maybe the part of how to pass CFLAGS correctly in the proposal written above can be replaced by more general guideline like following.

Alternative proposal (for both Gem and non-Gem) 

export CONFIGURE_ARGS="--with-cflags='%{optflags}'"

should be used to pass CFLAGS to Makefile correctly. This also applies to Ruby Gems.

Retrieved from "https://fedoraproject.org/wiki/Archive:PackagingDrafts/RubyGem_with_C_code"