Bug 777111

Summary:	sys-apps/portage: score binary packages by difference between built USE configuration and desired USE configuration as alternative to --binpkg-respect-use
Product:	Portage Development	Reporter:	Zac Medico <zmedico>
Component:	Binary packages support	Assignee:	Portage team <dev-portage>
Status:	CONFIRMED ---
Severity:	normal	CC:	esigra, gentoo, srcshelton, zmedico
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	All
See Also:	https://bugs.gentoo.org/show_bug.cgi?id=772380 https://bugs.gentoo.org/show_bug.cgi?id=780390 https://bugs.gentoo.org/show_bug.cgi?id=934962 https://bugs.gentoo.org/show_bug.cgi?id=942601
Whiteboard:
Package list:		Runtime testing required:	---
Bug Depends on:
Bug Blocks:	155723

Description Zac Medico gentoo-dev

2021-03-18 20:18:38 UTC

When selecting binary packages, there are cases where --binpkg-respect-use may be too strict, and it would be helpful to be able to select packages which minimize differences between built USE configuration and desired USE configuration. We can use difflib to implement this, in the same way as emerge --search uses it to implement fuzzy search.

Comment 1 Emily Rowlands 2021-03-18 20:39:35 UTC

If this were implemented, there should be a way of specifying the "importance" of a USE flag so that an important difference isn't overlooked for a minor one. For example in sys-apps/glibc, USE=headers-only has a much greater impact on the resulting package than the doc flag. Another point would be having ABI-changing flags have a very high score. Unfortunately, my suggestion here may require a future EAPI change or an additional attribute in the <use> element in metadata.xml since it is not feasible to hard-code that kind of information into portage itself.

Comment 2 Zac Medico gentoo-dev

2021-03-18 21:38:18 UTC

We can allow users to side-load ranks so that they can be used without any EAPI support.

Comment 3 Zac Medico gentoo-dev

2021-03-18 21:43:30 UTC

(In reply to Emily Rowlands from comment #1)
> If this were implemented, there should be a way of specifying the
> "importance" of a USE flag so that an important difference isn't overlooked
> for a minor one.

I suppose we should also allow this rank to have different values per package/USE flag combination.

Comment 4 Zac Medico gentoo-dev

2024-07-29 00:15:00 UTC

For the USE flag priority / rank, we can start with use.force and/or use.mask flags, since a mismatch in one of those like USE=systemd for example would be comparatively undesirable.

IUSE_IMPLICIT, USE_EXPAND_IMPLICIT, and USE_EXPAND_UNPREFIXED settings should also be used to increase USE flag priority / rank.