Building RPM packages of SCons-based projects

Easy delivery and installation of a project helps massively with user acceptance. Take a look at all the app stores and user friendly package managers. For quite some of our Linux specific projects we build RPM-Packages using a build farm and the Jenkins continuous integration (CI) server. Sometimes we have to package dependencies which are not available for the used distributions. Some days ago we packaged some projects that were using the SCons build system. Using SCons is quite simple but there is one caveat to make it work nicely with rpmbuild: You have to fiddle with the installation prefixes. Let’s have a look at the build and install stanza of the SPEC-file:

# build stanza
%build
scons PREFIX=/usr LIBDIR=%_libdir all

# install stanza
%install
rm -rf $RPM_BUILD_ROOT
scons PREFIX=/usr LIBDIR=%_libdir install --install-sandbox="$RPM_BUILD_ROOT"

The two crucial parts here are:

1. Setting the correct prefixes in build and install because the build could use configured paths which have to match the situation of the installed result
2. The --install-sandbox command line switch which tells SCons to install everything under the specified location instead of directly to the system. This allows rpmbuild to put the artifacts into the package using the correct layout.

Using the above advice it should be quite easy to build nicely working RPM packages out of projects using SCons.