From Fedora Project Wiki

What Is Depcheck?

Depcheck was created to detect package builds with broken dependencies. As the test matures, it will eventually be a part of the rel-eng process to prevent broken builds from being pushed to the testing or stable package repositories.

How Does Depcheck Work?

Depcheck uses libsolv to compute package dependencies of proposed updates and evaluates whether these dependencies are satisfied. Always the whole set of builds submitted to a certain repository (fedora, updates or updates-testing) is considered together -- even though Bodhi update should be completely standalone, depcheck will be able to find and resolve dependencies between individual updates, as long as they are submitted together (request to be pushed to the same repository at the same time).

Known deficiencies

At the moment, depcheck only decides whether each of the submitted builds is installable. This is equivalent to trying to install that build into a completely empty environment (no RPM packages pre-installed). If some other package build (that is already present in the target repository) gets broken as a result of this, that's not currently detected by depcheck. See ticket 357 and Current State of Depcheck and Paths Forward.

Understanding Failures

Unsatisfied dependencies

Looking at an example log, we see the following excerpt:

not ok - depcheck for Bodhi update openstack-zaqar-2014.2-0.3.b3.fc21	# FAIL 
  arch: i386
    output: |-
      Build openstack-zaqar-2014.2-0.3.b3.fc21 failed depcheck
      nothing provides python-oslo-utils needed by openstack-zaqar-2014.2-0.3.b3.fc21.noarch
      nothing provides python-oslo-utils needed by openstack-zaqar-2014.2-0.3.b3.fc21.noarch
  item: openstack-zaqar-2014.2-0.3.b3.fc21
  outcome: FAILED
  summary: openstack-zaqar-2014.2-0.3.b3.fc21 into F21 testing
  type: bodhi_update

This is a similar message that you should see when trying to install this package using Package-x-generic-16.pngdnf.

In this case, Package-x-generic-16.pngopenstack-zaqar requires python-oslo-utils, but at the time the test ran, this was not provided by any available package.

Fixing Failures

Fortunately, the fixes for depcheck errors tend to be relatively straight-forward and tend to fall into one of two categories listed below.

  1. Problems caused by your package
    Examine any changes to Provides, Requires or BuildRequires in the spec file. Ensure correct spelling of all dependencies and confirm that any changed requirements do resolve for the appropriate release. If the dependencies of your package have not changed, it's possible that other packages no longer satisfy the dependencies as expected. Read below for further guidance.
    The command repoquery is helpful to track dependencies.
  2. Problems caused by other package(s)
    If your package failed because the dependencies of other packages changed (features they were providing changed or were removed), update the requirements of your package or consult with maintainers of the corresponding packages.

Getting Help

If you still don't understand why your update failed the test, if you think there's something wrong in our test or its documentation or if you have any other suggestions, please contact us.

Additional Information