Basic Ebuild Troubleshooting

This is a brief explanation of how one might trouble shoot local emerge/ebuild failures. It is in no way comprehensive, and is only meant as an introduction to the topic:

Emerge Errors During build_image:

When following the Chromium OS Developer Guide emerge errors can be encountered for missing ebuild. A error that can be encountered when running build_image is:

emerge: there are no ebuilds to satisfy XYZ

Where XYZ is a library or other missing package.

This can be resolved by running:

emerge-$BOARD XYZ

Then recalling build_image:

./build_image --board=${BOARD} --noenable_rootfs_verification dev


[1] Autotest ebuild documentation

[2] Chromite documentation

From within the chroot, try running the a new test through run_remote_tests, as described in the codelab on autotest client tests, without actually adding it to an ebuild. This might give you an error about not being able to find kernel_HdParmBasic’s control file.

To resolve this, from within chroot:

1. Find the package with autotest tests:

emerge --search autotest | grep tests

2. Dry emerge it and look for your test in the output:

emerge-lumpy -pv chromeos-base/autotest-tests

    Two things to note:

    a. The first line will say something like: “chromeos-base/autotest-tests-0.0.1-r3531“

     This means it’s emerging the r3531 ebuild. 

       Since we would like it to use our local bits, we need to cros_workon the package.

    b. You will not find kernel_HdParmBasic in the output.

3. cros_workon the appropriate package:

    cros_workon --board=<board name> start <package name>

    eg: cros_workon --board=lumpy start autotest-tests

    emerge the package: emerge-<board name> <package name>

    eg: emerge-lumpy -pv chromeos-base/autotest-tests

    Two things to note:

    a. The first line will say something like:


This is good, it means it’s pulling local bits.

    b. You still will not find kernel_HdParmBasic in the output.

This is because your new test hasn’t been added to the ebuild yet.

4. Edit the ebuild to include your test:

Find the ebuild file: find -iname “autotest-tests-9999.ebuild” from src/third_party/. 

      a. It will most probably point you to:


      b. open this file and add “+test_kernel_HdParmBasic” in the IUSE_TESTS section.

5. Emerge the new folder:

     a. Make sure you’re cros_working on the right packages:

        cros_workon --board=lumpy list

        should show autotest_tests

     b. Make sure the emerge will touch kernel_HdParmBasic:

        emerge-lumpy -pv chromeos-base/autotest-tests | grep kernel_HdParmBasic

     c. Actual emerge:

        emerge-lumpy chromeos-base/autotest-tests


6. Check the staging area for your new test:

      eg: ls /build/lumpy/usr/local/autotest/client/site_tests/kernel_HdParmBasic

7. Re-run the run_remote command and look for the results directory:

    you should see a line like:

        >>> Details stored under /tmp/run_remote_tests.KTQ4
    Alternatively, you can specify your own results directory using ‘--results_dir_root’.

Some common ebuilds to cros_workon and emerge:

  • autotest-all (Meta ebuild for all packages providing tests),
  • autotest-factory (Autotest Factory tests),
  • autotest-chrome (Autotest tests that require chrome_test or pyauto deps),
  • autotest-tests (Pure Autotest tests),  
  • autotest (Autotest scripts and tools).
If you have come this far, you may also be interested in reading the autotest client tests codelab.