CentOS Mock Usage

Mock options and sample invocations

common Mock options

Mock can be invoked with a fair number of options; typically when rebuilding packages, only a few specific options are required. See /usr/bin/mock --help for the complete list of options and defaults, and mock(1) for additional documentation and examples.

option flag	provides	possible values
-r CHROOT	name of the CHROOT, usually $dist-$release-$arch, but other configs may exist. Corresponding configs are in /etc/mock/*.cfg	epel-5-i386, fedora-13-ppc, epel-5-jpackage-x86_64
--resultdir	path for resulting files (source / binary rpms, and logs). This can be any arbitrary path on the filesystem, writable by the invoking user	any path writable to the invoking user; it may be convenient to drop results in a directory hierarchy based on release/version/architecture
--arch	Sets kernel personality(). Note that arch is typically already set in the build environment .cfg, though this option can be useful when building e.g. kernels (where arch=i686) to override the default	i386, i686, x86_64, ppc. limited by arch of build host
--uniqueext	Arbitrary, unique extension to append to buildroot directory name. This allows simultaneous builds to occur	$USERID, or some other unique identifier

A sample invocation:

throck@buildhost-01% /usr/bin/mock -r epel-5-i386 \
   --resultdir=/srv/results/throck/centos-5/i386/collectd-4.9.1-3.el5 \
   --uniqueext=throck \
   --arch=i386 \
   /srv/results/throck/srpms/collectd-4.9.1-3.el5.src.rpm

sample mock session details

Here is an example mock invocation, which is being used to rebuild the web100_userland package for the i386 architecture, using the EPEL-enabled CentOS 5 build environment configuration:

throck@buildhost-01% /usr/bin/mock -r epel-5-i386 --resultdir=/srv/results/throck/centos-5/i386/web100_userland-1.7-3.el5 --uniqueext=throck --arch=i386 /home/throck/rpm/SRPM/web100_userland-1.7-3.el5.src.rpm
INFO: mock.py version 1.0.7 starting...
State Changed: init plugins
State Changed: start
INFO: Start(/home/throck/rpm/SRPM/web100_userland-1.7-3.el5.src.rpm)  Config(epel-5-i386)
State Changed: lock buildroot
State Changed: clean
State Changed: init
State Changed: lock buildroot
Mock Version: 1.0.7
INFO: Mock Version: 1.0.7
INFO: enabled root cache
State Changed: unpacking root cache
INFO: enabled yum cache
State Changed: cleaning yum metadata
State Changed: running yum
State Changed: setup
State Changed: build
INFO: Done(/home/throck/rpm/SRPM/web100_userland-1.7-3.el5.src.rpm) Config(epel-5-i386) 1 minutes 34 seconds
INFO: Results and/or logs in: /srv/results/throck/centos-5/i386/web100_userland-1.7-3.el5
INFO: Cleaning up build root ('clean_on_success=True')
State Changed: lock buildroot
State Changed: clean
throck@buildhost-01% 

This example session resulted in a successful build; examining the results directory we find:

throck@admin-test-01% ls -la /srv/results/throck/centos-5/i386/web100_userland-1.7-3.el5
total 1028
drwxrwxr-x  2 throck throck   4096 Aug 10 00:28 .
drwxr-xr-x 56 throck throck   4096 Sep  7 16:38 ..
-rw-rw-r--  1 throck throck  65945 Aug 10 00:28 build.log
-rw-rw-r--  1 throck throck  20412 Aug 10 00:28 root.log
-rw-rw-r--  1 throck throck    421 Aug 10 00:28 state.log
-rw-r--r--  1 throck mock   146881 Aug 10 00:28 web100_userland-1.7-3.el5.i386.rpm
-rw-r--r--  1 throck mock   487671 Aug 10 00:27 web100_userland-1.7-3.el5.src.rpm
-rw-r--r--  1 throck mock   291894 Aug 10 00:28 web100_userland-debuginfo-1.7-3.el5.i386.rpm

Of particular interest (aside from the resulting rpm's) are the root.log, which contains a record of the creation of the build root, including specific details about any yum transactions that were run to meet build dependencies, and the build.log, that contains the details of the mock invocation, the source compilation (if any), and the creation of the resulting package(s).

If the package build fails, it's also possible to examine the buildroot (assuming you've configured Mock to not cleanup_on_failure)

---

tips and troubleshooting

setting up a mock shell function for easier command line invocation

Typing out the mock invocation for every build can be tedious; using a shell function similar to the following provides a method for shortcutting the command line:

mockbuild ()
{
    MYCFG=$1;
    MYDISTRO=$2;
    MYARCH=$3;
    MYSRPM=$4;
    shift;
    shift;
    shift;
    shift;
    EXTRAS=$*;
    if [ -z ${MYSRPM} ]; then
        echo "mockbuild \$CFG \$DISTRO \$ARCH \$SRPM";
        return;
    fi;
    if [ -z "`rpm -qp $MYSRPM 2>/dev/null`" ]; then
        echo "invalid SRPM";
        return;
    fi;
    RDIR="/srv/results/${USERNAME}/${MYDISTRO}/${MYARCH}/`rpm -qp ${MYSRPM} 2>/dev/null`";
    echo "/usr/bin/mock -r ${MYCFG} --resultdir=${RDIR} --uniqueext=$USER --arch=${MYARCH} ${MYSRPM}";
    echo "Extras: $EXTRAS"
}

The expected arguments are:

variable	expected value	example
MYCFG	The mock configuration to use, minus the .cfg; see /etc/mock/ for a list of valid configurations	epel-5-i386, epel-5-x86_64.cfg
MYDISTRO	name of the target distro; will be used along with $for the --resultdir` path	centos-5, perfsonar-ps
MYARCH	Target arch	i386, x86_64
MYSRPM	Path to your Source RPM package	/home/throck/rpm/SRPM/web100_userland-1.7-3.el5.src.rpm, /tmp/mypackage-1.0-1.src.rpm

Invoking this function in a shell

throck@psdev% mockbuild epel-5-i386 centos-5 i386 /home/throck/rpm/nptoolkit/SRPM/web100_userland-1.7-3.el5.src.rpm

...would then be expanded to:

throck@psdev% /usr/bin/mock -r epel-5-i386 --resultdir=/srv/results/throck/centos-5/i386/web100_userland-1.7-3.el5 --uniqueext=throck --arch=i386 /home/throck/rpm/SRPM/web100_userland-1.7-3.el5.src.rpm

troubleshooting mock builds

If a build fails, the session will return an ERROR, and a hint at the reason for failure. In this example, e.g., a build dependency is missing:

ERROR: Bad build req: No Package Found for I2util. Exiting.

In that case, simply making the necessary package available (see the section on 'creating holding repos') will likely negate the problem. Sometimes, however, the failure cannot be interpreted by mock, and the reason will be given as:

ERROR: Command failed. See logs for output.

At this point, looking at the build.log for specific errors related to the failure is necessary. There can be a variety of failures when rebuilding packages; some will be completely apparent, and others elusive.

Some common failures include:

• the buildroot is being included in installed files

Found '/var/tmp/bwctl-1.3-3-buildroot' in installed files; aborting

This can typically be fixed by defining/adjusting the --prefix passed to %configure in %build.

• make test (esp. with perl modules) fails at test_dynamic (which is a module, not a build issue):

...
Failed 4/13 test scripts, 69.23% okay. 10/148 subtests failed, 93.24% okay.
make: *** [test_dynamic] Error 255
error: Bad exit status from /var/tmp/rpm-tmp.83954 (%check)
RPM build errors:
    Bad exit status from /var/tmp/rpm-tmp.83954 (%check)
Child returncode was: 1
EXCEPTION: Command failed. See logs for output.

• a patch included in the source rpm won't apply cleanly:

Patch #0 (ELRepo-sk98lin-10.85.8.3-el5.patch):
+ echo 'Patch #0 (ELRepo-sk98lin-10.85.8.3-el5.patch):'
+ patch -p1 -s
1 out of 1 hunk FAILED -- saving rejects to file h/skcsum.h.rej
1 out of 1 hunk FAILED -- saving rejects to file h/skdrv1st.h.rej
1 out of 1 hunk FAILED -- saving rejects to file h/skdrv2nd.h.rej
1 out of 1 hunk FAILED -- saving rejects to file h/skgepnmi.h.rej
error: Bad exit status from /var/tmp/rpm-tmp.48216 (%prep)