From f7c51606f0eae56f0cf52c54713f7816d8e9f97c Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Tue, 18 Jun 2019 17:23:39 -0400 Subject: hooks: support external hooks running different Python version As we convert repo to support Python 3, the version of Python that we use might not be the version that repo hooks users have written for. Since repo upgrades are not immediate, and not easily under direct control of end users (relative to the projects maintaining the hook code), allow hook authors to declare the version of Python that they want to use. Now repo will read the shebang from the hook script and compare it against the version of Python repo itself is running under. If they differ, we'll try to execute a separate instance of Python and have it load & execute the hook. If things are compatible, then we still use the inprocess execution logic that we have today. This allows repo hook users to upgrade on their own schedule (they could even upgrade to Python 3 ahead of us) without having to worry about their supported version being exactly in sync with repo's. Bug: https://crbug.com/gerrit/10418 Change-Id: I97c7c96b64fb2ee465c39b90e9bdcc76394a146a Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/228432 Reviewed-by: David Pursehouse Tested-by: Mike Frysinger --- docs/python-support.md | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'docs/python-support.md') diff --git a/docs/python-support.md b/docs/python-support.md index af19cd05..35806de7 100644 --- a/docs/python-support.md +++ b/docs/python-support.md @@ -28,5 +28,20 @@ The master branch will require Python 3.6 at a minimum. If the system has an older version of Python 3, then users will have to select the legacy Python 2 branch instead. +### repo hooks +Projects that use [repo hooks] run on independent schedules. +They might migrate to Python 3 earlier or later than us. +To support them, we'll probe the shebang of the hook script and if we find an +interpreter in there that indicates a different version than repo is currently +running under, we'll attempt to reexec ourselves under that. + +For example, a hook with a header like `#!/usr/bin/python2` will have repo +execute `/usr/bin/python2` to execute the hook code specifically if repo is +currently running Python 3. + +For more details, consult the [repo hooks] documentation. + + +[repo hooks]: ./repo-hooks.md [repo launcher]: ../repo -- cgit v1.2.3-54-g00ecf