Created attachment 660978 [details] Portage output I have a bunch of packages installed in earlier versions due to python2.7 target deps. Portage keeps throwing a lot of slot conflict spam at every @world upgrade due to them but so far was able to keep working (and installing old versions for these packages). However, when I've unmasked new pypy3 version for testing and this involves subslot rebuild for some of these packages, Portage goes crazy and is unable to proceed.
(this can be resolved by masking all the conflicting new versions but this isn't exactly user-friendly)
(In reply to Michał Górny from comment #0) > I have a bunch of packages installed in earlier versions due to python2.7 > target deps. That triggers backtracking, and if there are enough missed updates then eventually you'll hit the backtracking limit. When that happens, we have a couple of options: 1) Use a larger --backtrack argument. 2) Improve the backtracking algorithm so that less backtracking is needed.
A glaring problem with the current backtracking approach is that it only eliminates one package at a time. For example, consider these versions of setuptools which available: dev-python/setuptools-50.3.0 dev-python/setuptools-50.2.0 dev-python/setuptools-50.1.0 dev-python/setuptools-49.6.0 dev-python/setuptools-46.4.0-r2 dev-python/setuptools-46.4.0-r1 When emerge encounters its first setuptools slot conflict, it will add dev-python/setuptools-50.3.0 to its runtime package mask, and then start backtracking. What we really want it to do is to add all of these versions to its runtime package mask at the same time: dev-python/setuptools-50.3.0 dev-python/setuptools-50.2.0 dev-python/setuptools-50.1.0 dev-python/setuptools-49.6.0 If it does that, then it won't have to waste time backtracking in order to eliminate the other versions which will not satisfy the python_targets_python2_7 USE dependency.
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/proj/portage.git/commit/?id=302a93e5857ff56d43ee0b9dabee9f00d907a8ad commit 302a93e5857ff56d43ee0b9dabee9f00d907a8ad Author: Zac Medico <zmedico@gentoo.org> AuthorDate: 2020-09-13 01:42:30 +0000 Commit: Zac Medico <zmedico@gentoo.org> CommitDate: 2020-09-19 20:22:41 +0000 Add unit test demonstrating excessive backtracking for bug 743115 Due to excessive backtracking, this test case currently needs at least --backtrack=21 to succeed. Bug: https://bugs.gentoo.org/743115 Signed-off-by: Zac Medico <zmedico@gentoo.org> .../resolver/test_slot_operator_missed_update.py | 112 +++++++++++++++++++++ 1 file changed, 112 insertions(+)
Patch posted for review: https://archives.gentoo.org/gentoo-portage-dev/message/a74b538fcbf126a0d65dccc0fde470f2 https://github.com/gentoo/portage/pull/624
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/proj/portage.git/commit/?id=f64310749f176f8921b72ce282b4294efe81c3f0 commit f64310749f176f8921b72ce282b4294efe81c3f0 Author: Zac Medico <zmedico@gentoo.org> AuthorDate: 2020-09-19 21:32:41 +0000 Commit: Zac Medico <zmedico@gentoo.org> CommitDate: 2020-09-20 22:27:32 +0000 _slot_confict_backtrack: minimize conflict atoms (bug 743631) Prefer choices that minimize conflict atoms, so that choices which satisfy all parents are preferred. This reduces the minimum necessary backtrack tries from 21 to 7 for the unit test related to bug 743115. Bug: https://bugs.gentoo.org/743115 Bug: https://bugs.gentoo.org/743631 Signed-off-by: Zac Medico <zmedico@gentoo.org> lib/_emerge/depgraph.py | 6 ++++++ lib/portage/tests/resolver/test_slot_operator_missed_update.py | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-)
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/proj/portage.git/commit/?id=9afc5d5a808ca66173b1d803469cd44bc24e99be commit 9afc5d5a808ca66173b1d803469cd44bc24e99be Author: Zac Medico <zmedico@gentoo.org> AuthorDate: 2020-09-19 23:18:16 +0000 Commit: Zac Medico <zmedico@gentoo.org> CommitDate: 2020-09-20 22:59:06 +0000 _slot_confict_backtrack: group similar missed updates (bug 743115) When a slot conflict occurs due to a missed update, and some other similar update(s) are available, add the similar update(s) to the runtime package mask for the same backtracking choice. This reduces minimum number of backtrack tries required to solve the test case for bug 743115 from 7 to 4, where the difference of 3 corresponds to the number of other similar setuptools updates available. Bug: https://bugs.gentoo.org/743115 Signed-off-by: Zac Medico <zmedico@gentoo.org> lib/_emerge/depgraph.py | 25 ++++++++++++++++++---- lib/_emerge/resolver/backtracking.py | 7 +++--- .../resolver/test_slot_operator_missed_update.py | 2 +- 3 files changed, 26 insertions(+), 8 deletions(-)
The bug has been referenced in the following commit(s): https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=862266358f01efa90c12d182d1f85a3014b80439 commit 862266358f01efa90c12d182d1f85a3014b80439 Author: Zac Medico <zmedico@gentoo.org> AuthorDate: 2020-09-21 05:35:06 +0000 Commit: Zac Medico <zmedico@gentoo.org> CommitDate: 2020-09-21 05:59:31 +0000 sys-apps/portage: Bump to version 3.0.8 #404157 emerge: --keep-going support pkg_pretend failures #644246 Add mercurial sync support #710432 emerge: Enable parallel-fetch during pkg_pretend #743115 emerge: Fix slot conflict backtracking to group similar missed updates into a single backtracking try #743631 emerge: Fix slot conflict backtracking to prefer choices that satisfy all dependencies Bug: https://bugs.gentoo.org/739718 Bug: https://bugs.gentoo.org/404157 Bug: https://bugs.gentoo.org/644246 Bug: https://bugs.gentoo.org/710432 Bug: https://bugs.gentoo.org/743115 Bug: https://bugs.gentoo.org/743631 Package-Manager: Portage-3.0.8, Repoman-3.0.1 Signed-off-by: Zac Medico <zmedico@gentoo.org> sys-apps/portage/Manifest | 1 + sys-apps/portage/portage-3.0.8.ebuild | 267 ++++++++++++++++++++++++++++++++++ 2 files changed, 268 insertions(+)
