From Fedora Project Wiki

Using Koji in Fedora

The Koji Build System is Fedora's RPM buildsystem. Packagers use the koji client to request package builds and get information about the buildsystem. Koji runs on top of Mock to build RPM packages for specific architectures and ensure that they build correctly.

There is also a simplified Chinese edition.

Installing Koji

Installing the Koji CLI

Everything you need to use Koji (and be a Fedora contributor) can be installed in a single step:

yum install fedora-packager

fedora-packager provides useful scripts to help maintain and setup your koji environment. Additionally, it includes dependencies on the Koji CLI, so it will be installed when you install fedora-packager. The command is called koji and is included in the main koji package. By default the koji tool authenticates to the central server using Kerberos. However SSL and username/password authentications are available. You will need to have a valid authentication token to use many features. However, many of the read-only commands will work without authentication.

Fedora Account System (FAS2) Setup

Initial Fedora Setup

In order to interface with the koji server, maintainers will need to run


Each user on a system will need to run fedora-packager-setup if they wish to use Koji to build Fedora packages. Each user has their own certificates that authenticate them.

Plague users rejoice!
For existing users of plague (the old build system that preceded Koji), fedora-packager-setup will use your existing certificates. If you did not have plague before, it will get the server CA certs and tell you where to get your user cert.
Fedora Certificates

Koji uses three certificates:

~/.fedora.cert (specific to the Fedora Maintainer)
This cert is generated from this form in FAS. It should have been generated when you became maintainer. You may need to refresh it when it expires.

the following are downloaded automatically by fedora-packager-setup and dont need to be manually setup

~/.fedora-upload-ca.cert (The certificate for the Certificate Authority used to sign the user keys.)
It can be manually downloaded from here or fedora-packager-setup or fedora-cert -n should fetch it. using the CLI is prefered.
~/.fedora-server-ca.cert (The certificate for the Certificate Authority used to sign the build system's server keys.)
It can be downloaded manually from here or fedora-packager-setup should fetch it.
RHEL6 cert bug
If you're using RHEL6, an incompatibility between RHEL6's openssl and nss causes certificates downloaded from fas to fail to work with some fedpkg tools. [Bug 631000 rhel6 openssl creates PKCS#8 encoded PEM RSA private key files, nss can't read them]. The cert can be made compatible using this command: (openssl x509 -in ~/.fedora.cert -text; echo; openssl rsa -in ~/.fedora.cert) >
Koji Config

The global local client configuration file for koji is /etc/koji.conf. You should not need to change this from the defaults for building Fedora packages, as running fedora-packager-setup will create a set of configuration files in ~/.koji/ file for your user these will allow you to use the primary build system as well as secondary arch build systems.

The web interface

The primary interface for viewing Koji data is a web application. It is available at . Most of the interface is read-only, but if you are logged in (see below) and have sufficient privileges there are some actions that can be performed though the web. For example:

  • Cancel a build
  • Resubmit a failed task
  • Setup a notification

Those with admin privileges will find additional actions, such as:

  • Create/Edit/Delete a tag
  • Create/Edit/Delete a target
  • Enable/Disable a build host

The web site utilizes SSL authentication. In order to log in you will need a valid SSL certificate and your web browser will need to be configured to trust the SSL cert. Instructions on how to do this are printed when running fedora-packager-setup.


With Koji you can setup a notification requests, to make sure you do not miss when a package you care about gets built. Login and scroll to the bottom of the page, there you should find a Add a notification link and a list of your configured notifications.

Building with fedpkg targets

Every push is automatically tagged via git. All you have done to build the package is to run,

fedpkg build

This will trigger a build request for the branch. Easy!

It is also possible to target a specific koji tag as follows:

fedpkg build --target TARGET

for example, if building on rawhide against a special tag created by rel-eng for updating API for many packages, e.g. dist-f14-python you would use the following:

fedpkg build --target 'dist-f14-python'

Chained builds

chain-builds only work when building on the devel/ branch (aka rawhide). To chain-build packages to update a released OS version, open a ticket with the Release Engineering team asking for earlier built packages to be included in the proper buildroot. For Fedora packages, select component 'koji'. For EPEL packages, select component 'epel'.

Sometimes you want to make sure than one build succeeded before launching the next one, for example when you want to rebuild a package against a just rebuilt dependency. In that case you can use a chain build with:

fedpkg chain-build --target 'libwidget libgizmo'

The current package is added to the end of the CHAIN list. Colons (:) can be used in the CHAIN parameter to define groups of packages. Packages in any single group will be built in parallel and all packages in a group must build successfully and populate the repository before the next group will begin building. For example:

fedpkg chain-build libwidget libaselib : libgizmo :

will cause libwidget and libaselib to be built in parallel, followed by libgizmo and then the currect directory package. If no groups are defined, packages will be built sequentially.

If a build fail, following builds are canceled but the builds that already succeeded are pushed to the repository.

Scratch Builds

Sometime it is useful to be able to build a package against the buildroot but without actually including it in the release. This is called a scratch build. The following section covers using koji directly as well as the fedpkg tool to do scratch builds. To create a scratch build from changes you haven't committed, do the following:

rpmbuild -bs foo.spec
koji build --scratch dist-rawhide foo.srpm

From the latest git commit:

koji build --scratch dist-rawhide 'git url'

Warning: Scratch builds will not work correctly if your .spec file does something different depending on the value of %fedora, %fc9, and so on. Macro values like these are set by the builder, not by koji, so the value of %fedora will be for whatever created the source RPM, and not what it's being built on. Non-scratch builds get around this by first re-building the source RPM.

If you are have committed the changes to git and you are in the current branch, you can do a scratch build with fedpkg tool which wraps the koji command line tool with the appropriate options:

fedpkg scratch-build

if you want to do a scratch build for a specific architecture, you can type:

fedpkg scratch-build-<archs>

<archs> can be a comma separated list of several architectures.

finally is possible to combine the scratch-build command with a specific koji tag in the form:

fedpkg scratch-build --target TARGET

fedpkg scratch-build --help or koji build --help for more information.

Build Failures

If your package fails to build, you will see something like this:

420066 buildArch kernel-2.6.18-1.2739.10.9.el5.jjf.215394.2.src.rpm,
ia64): open ( -> FAILED: BuildrootError:
error building package (arch ia64), mock exited with status 10

You can figure out why the build failed by looking at the log files. If there is a build.log, start there. Otherwise, look at init.log.

Logs can be found via the web interface in the Task pages for the failed task. Alternatively the koji client can be used to view the logs via the watch-logs command. See the help output for more details.

Advanced use of Koji

We've tried to make Koji self-documenting wherever possible. The command line tool will print a list of valid commands and each command supports --help. For example:

$ koji help

Koji commands are:
build                Build a package from source
cancel-task          Cancel a task
help                 List available commands
latest-build         Print the latest rpms for a tag
latest-pkg           Print the latest builds for a tag
$ koji build --help

usage: koji build [options]  tag URL
(Specify the --help global option for a list of other help options)

-h, --help            show this help message and exit
--skip-tag            Do not attempt to tag package
--scratch             Perform a scratch build
--nowait              Don't wait on build

Using koji to generate a mock config to replicate a buildroot

koji can be used to replicate a build root for local debugging

koji mock-config --help
Usage: koji mock-config [options] name
(Specify the --help global option for a list of other help options)

  -h, --help            show this help message and exit
  --arch=ARCH           Specify the arch
  --tag=TAG             Create a mock config for a tag
  --task=TASK           Duplicate the mock config of a previous task
                        Duplicate the mock config for the specified buildroot
  --mockdir=DIR         Specify mockdir
  --topdir=DIR          Specify topdir
  --topurl=URL          url under which Koji files are accessible
                        Change the distribution macro
  -o FILE               Output to a file

for example to get the latest buildroot for dist-f12-build run

koji mock-config --tag dist-f12-build --arch=x86_64 --topurl= dist-f12

you will need to pass in --topurl= to any mock-config command to get a working mock-config from fedoras koji.

Using Koji to control tasks

List tasks:

koji list-tasks

List only tasks requested by you:

koji list-tasks --mine

requeue an already-processed task: general syntax is: koji resubmit [options] taskID

koji resubmit 3

Building a Package with the command-line tool

Instead of using the fedpkg target, you can also directly use the command_line tool, koji.

To build a package, the syntax is:

$ koji build <build target> <git URL>

For example: {{Admon/warning | Replace dist-f14 with the tag you wish to build against, e.g., dist-rawhide

$ koji build dist-f14 'git url'

The koji build command creates a build task in Koji. By default the tool will wait and print status updates until the build completes. You can override this with the --nowait option.

Koji tags and packages organization


In Koji, it is sometimes necessary to distinguish between a package in general, a specific build of a package, and the various rpm files created by a build. When precision is needed, these terms should be interpreted as follows:

  • Package: The name of a source rpm. This refers to the package in general and not any particular build or subpackage. For example: kernel, glibc, etc.
  • Build: A particular build of a package. This refers to the entire build: all arches and subpackages. For example: kernel-2.6.9-34.EL, glibc-2.3.4-2.19.
  • RPM: A particular rpm. A specific arch and subpackage of a build. For example: kernel-2.6.9-34.EL.x86_64, kernel-devel-2.6.9-34.EL.s390, glibc-2.3.4-2.19.i686, glibc-common-2.3.4-2.19.ia64

Tags and targets

Koji organizes packages using tags. In Koji a tag is roughly a collection of packages:

  • Tags support inheritance
  • Each tag has its own list of valid packages (inheritable)
  • Package ownership can be set per-tag (inheritable)
  • When you build you specify a target rather than a tag

A build target specifies where a package should be built and how it should be tagged afterwards. This allows target names to remain fixed as tags change through releases.

Koji commands for tags


You can get a full list of build targets with the following command:

$ koji list-targets

You can see just a single target with the --name option:

$ koji list-targets --name dist-f14

Name                           Buildroot                      Destination
dist-f14                     dist-f14-build                 dist-f14

This tells you a build for target dist-f14 will use a buildroot with packages from the tag dist-f14-build and tag the resulting packages as dist-f14.

Watch out: You probably don't want to build against dist-rawhide. If Fedora N is the latest one out, to build to the next one, choose dist-f{N+1}.


You can get a list of tags with the following command:

$ koji list-tags

As mentioned above, each tag has its own list of packages that may be placed in the tag. To see that list for a tag, use the list-pkgs command:

$ koji list-pkgs --tag dist-f14

The first column is the name of the package, the second tells you which tag the package entry has been inherited from, and the third tells you the owner of the package.

Latest Builds

To see the latest builds for a tag, use the latest-pkg command:

$ koji latest-pkg --all dist-f14

The output gives you not only the latest builds, but which tag they have been inherited from and who built them.