This page documents the process of upgrading a Portage package in our source to the latest upstream version. These instructions are intended for Chromium OS developers.
The upgrade process documented here uses a script, called cros_portage_upgrade, developed to help automate/simplify this process. It is not required that you use this script, and if you are confident that you can update packages in another way you are free to do so. Some of the FAQ on this page may still be of use to you, in any case.
If you have done this before and just want a quick reminder of the steps, or you are someone who just doesn't like reading, then this is for you:
The following assumptions are made with these instructions:
Any Portage packages, upstream included, can be marked as stable or unstable for any architecture. You don't have to know anything more about this detail unless you need to upgrade a package to an unstable version. However, this happens somewhat frequently. Perhaps a feature you need is only available in the absolute latest version of a package, but that version has not been marked stable for x86, yet. If you do need to upgrade to an unstable version check the appendix entry below.
The chromiumos source has projects that are portage "overlays", all under src/third_party. Three of them are of interest here.
Check the package status spreadsheet and write down which package or packages you want to upgrade, using their full "category/package" name (e.g. sys-apps/dbus). Decide whether you want to upgrade them to the latest stable or unstable versions. Generally, your first choice should be to upgrade packages to the latest stable upstream version.
Note whether any of the packages you need to upgrade are locally patched (as indicated in the spreadsheet). This means that somebody, possibly you, has made a patch to the package that we are using right now. It is important to determine what should happen to that patch after the upgrade. Inspect the git history for the patch, talk to the committer, inspect the patch, etc.
Decide which boards you want to try the upgrade for. You should include one board from each supported arch type (e.g. amd64, arm, x86), unless the package is only used on one arch for some reason (check the spreadsheet). Typically, there is no reason to specify more than one board per architecture type, unless you know of board-specific testing that must be done. If your package or packages are used on the host (see spreadsheet), then you want to upgrade for the host (which can be done at the same time as the boards). Many packages are used on a chromeos board as well as the host (the "host" is the chroot environment). Choose boards that you can test the upgrades on, or boards that you know the packages need to be tested on.
You probably want to 'repo sync' your entire source tree.
Prepare a new branch in the src/third_party/portage-stable project. This is where the upgrades will be staged/committed.
Now you need to setup all boards that you will need. For example, "x86-mario" and "tegra2_kaen". Note: this is not required if you're upgrading a host-only package.
For these instructions, let's say you want to upgrade "media-libs/alsa-lib", "media-sound/alsa-headers", and "media-sound/alsa-utils" on boards "x86-mario" and "tegra2_kaen". You plan to try the stable upstream versions first. These commands must be run from within your chroot. If you also need to upgrade on the host (chroot/amd64) use the --host option, which can be used in combination with the --board option or without it.
If the script runs all the way through without any problems the first time then you have no missing dependencies or other build-related obstacles to the upgrade. But you still need to test the upgrade results! The upgrade should be prepared as a commit in src/third_party/portage-stable. You should inspect/edit the commit message before uploading it, though.
If the script does not run all the way through the first time, it should give you the means to determine why. Typically, this means that one or more of the upgraded packages could not be built (using emerge) after the upgrade. This may be due to a package dependency that must also be upgraded, or a package mask that must be edited. In any case, you are given the output of the failing emerge command so that you can determine for yourself what is needed. Make the necessary change (perhaps adding another package to upgrade at the command line), then run again.
To upgrade to unstable versions, simply add the --unstable-ok option and follow the instructions. Or see the guidelines for upgrading to unstable versions below.
Run cros_portage_upgrade with --help to see addition options and usage. If you are having difficultly with this step please do not hesitate to contact mtennant (at chromium dot org) for assistance.
You may also need to clean up the files in your commit. Our convention is to only check in files that are used, and some upgrades come with extra files (such as unused patch files, for example). You can usually tell by inspecting the list of files and the ebuild whether any files are unused. You can remove these files from your commit with a command like the following within portage-stable:
If you already built your upgraded package, make sure to do it again after cleaning up extraneous files to verify that you haven't removed something important!
Use common sense, and your specific expertise, to test the upgraded packages. The changes are active in your source right now, so you can build your target boards to test. If your package is added to the host (chroot) you'll need to emerge it onto your chroot and test it there as well.
You probably want to run at least the suite:smoke tests for each board, which you can do by following the tips at https://sites.google.com/a/chromium.org/dev/chromium-os/testing (Googlers may also use the tips at goto/cros-test). In particular, you can use trybot to determine what effect your upgrade will have on the greenness of the waterfall.
Beyond the suite:smoke tests, test whatever you think makes sense given the packages you just upgraded.
When you are satisfied that the upgrade is safe to push, you still need to edit the commit message that was created for you by cros_portage_upgrade. Add a bug number, test details, and any other details you want.
Upload the usual way.
Then go through the usual code review process on gerrit.
After your changelist is through review and submitted to the tree, you will want to get off the branch you created in src/third_party/portage-stable. You know the drill.
repo abandon pkg_upgrade .
It is not uncommon for a package to be locally patched in the source now (typically any upstream package in the src/third_party/chromiumos-overlay overlay). To upgrade that package the patch will (probably) need to be applied again to the upgraded version. Let's say you upgraded the "foo/bar" package to upstream version "1.2.3", but you need to re-apply a patch to it that was previously applied to version "1.1.1" (perhaps "1.1.1-r1" is the active version now with the patch).
Allow the cros_portage_upgrade script to complete the pristine upgrade in src/third_party/portage-stable for the package first. Then copy the entire directory over to the analogous location under src/third_party/chromiumos-overlay, creating the directory if necessary (You can omit the ChangeLog and metadata.xml files; only the DIST lines of the Manifest file needs to be preserved.) You will commit the unaltered package as it is in the first changelist, but first you must mark it as unstable so that it will not be used. To do so, add a line like the following to src/third_party/chromiumos-overlay/profiles/default/linux/package.mask:
The above masks the specific package version "foo/bar-1.2.3" for all targets. (If your intent is to patch the ebuild only for certain platforms please speak to the build team as this is generally unnecessary and strongly discouraged.) Now you are ready to submit the pristine copy of the upstream package to chromiumos-overlay.
Next make a copy of the ebuild file with a revision suffix. For example:
Then re-apply the patch to the new revision ebuild, by copying the epatch line or lines in the previously patched ebuild (bar-1.1.1-r1.ebuild). Be sure to keep whatever patch files under the "files" directory are required for the patch, too. You might have to rename them (e.g. cp files/bar-1.1.1-something.patch files/bar-1.2.3-something.patch). Be careful to apply the patch responsibly, because the source file(s) the patch alters may have changed since the patch was created. If so, you can create a new patch or consult the original patch author (if not you).
To inspect the source files involved, both before and after patching, use the "ebuild" utility. For example, to see the source files for "foo/bar-1.2.3" before any patching run this inside chroot, use a command like the following (examples for the host, x86-mario, and tegra2_kaen, respectively):
The above will unpack source files and tell you where they are. You can inspect them to verify whether the source file(s) the patch touches have changed between versions. To see what the source files look like after patching, use the same commands as above but replace "unpack" with "prepare". Also, make sure your newly patched version is the version being picked up by the build system by running "equery which" inside chroot:
Make sure your new ebuild is the one being picked up. Your upgrade with patch is ready for testing now. Return to the testing step of the process above.
Remember to delete the new entry you made to the package.mask file.
Don't forget to discard the upgrade in portage-stable that cros_portage_upgrade created for you.
Some packages make use of eclasses, which are essentially ebuild code factored out into library files shared across multiple packages. If an ebuild file includes an inherit statement, then it uses an eclass. You don't have to check for this before you upgrade. The upgrade script will attempt to detect when an eclass must be upgraded along with a package upgrade, but if it is unable to you must upgrade the eclass yourself. If you are not sure how to do that please consult with a member of the build team.
If you need to upgrade a package to an unstable version for a compelling reason, then use the --unstable-ok option to the cros_portage_upgrade script and it will try to do the right thing. What it does is edit the KEYWORDS line (or lines) in the ebuild to mark specific architectures as stable. This is the only exception to the rule that packages in portage-stable should be unedited. You should inspect the resulting ebuild file or files to confirm that the edit worked correctly, and file a bug on cros_portage_upgrade if it did not.
Q: I ran the upgrade script multiple times, and the runtime dropped drastically after the first time. What gives?
Alternatively, you can clone your own copy of upstream origin/gentoo to point cros_portage_upgrade to, using the --upstream option. This will have the same runtime benefits if you run more than once. Do this inside your chroot:
Then add the following option when you run cros_portage_upgrade: --upstream=$HOME/gentoo-portage .
Q: Why doesn't the upgrade script just run on all boards/architectures that matter at once? Why do I have to specify them?
Q: Why doesn't the upgrade script run setup_board for me as needed?
Q: Why doesn't the upgrade script create the branch in src/third_party/portage-stable for me?
Q: Why can't the upgrade script create a complete commit message so no amend is needed, then do the upload and abandon steps as well?