Building RPMs Part 3

Now for part 3 of 'Building RPMs' we will be looking at how to determine what dependencies the package needs. In most cases, you would have installed software on your computer that may already have downloaded the libraries required to install your present application. For this reason it is best to use some sort of bare bone environment to install the software under that will than prompt you what libraries need to be installed. To setup a PC with a clean installation can be very time consuming. So instead we use a program called mock that chroots an environment that we could use to test what dependencies are required.

Lets install and configure mock. The best thing to do is create a user to do the mock builds because you don't want people to have access to your files while they test with mock. Add this also gives the user permissions to use mock using group permissions

adduser -m -G mock build

if your the only user on this system than you can just add your username to the mock group

usermod -a -G mock username

Once that's all done, it's time to test with mock. Let's assume you are building on a 64bit architecture and you're running Fedora 12 on that machine. If so this would be the command you would run:

#mock rebuild -r fedora-12-x86_64 --rebuild rpmbuild/SRPM/packagename*.src.rpm
#cat /var/lib/mock/fedora-12-x86_64/result/build.log

First command builds the source rpm package and the second will allow you to see the output of the build so you can determine what dependencies are needed.

When you find the required libraries than you have to find out the names for them to install them with 'yum' which than you would include them to the line in the spec file that says 'BuildRequires: " and add the library package name there. Now run mock again until you get no errors. Let's move to 'Koji'.

TO BE CONTINUED... (Build testing with Koji)