Bug 692786

Summary:	media-gfx/darktable: build scripts manipulate -march/-mtune compiler flags
Product:	Gentoo Linux	Reporter:	Sławomir Nizio <slawomir.nizio>
Component:	Current packages	Assignee:	Marek Szuba <marecki>
Status:	RESOLVED FIXED
Severity:	normal	CC:	jstein
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
Whiteboard:
Package list:		Runtime testing required:	---
Attachments:	Add the new USE flag.

Description Sławomir Nizio 2019-08-23 20:27:57 UTC

It's a matter of providing BINARY_PACKAGE_BUILD.
I checked that it works by:
- checking that vzeroupper instruction is used in libdarktable.so (seems to come from avx),
- and is absent with this flag being disabled. It's on by default as CPU detection is the current and default behaviour.

I'm not sure if there's a better USE flag. Either this, maybe bindist?

Comment 1 Sławomir Nizio 2019-08-23 20:29:23 UTC

Created attachment 587886 [details, diff]
Add the new USE flag.

Comment 2 Jonas Stein gentoo-dev

2019-08-23 23:35:54 UTC

please add a more detailed explanation, what the flag does.

Comment 3 Sławomir Nizio 2019-08-24 17:05:34 UTC

During building, darktable normally does autodetection of CPU features for an optimized build.

However, it is not suitable for distributable binary packages (e.g. Sabayon ones, or plain Portage binpkgs).

I've encountered a case (Sabayon bug 5817) that the build server built it with AVX features, but user's CPU lacked that, causing the application to crash with SIGILL.


So this flag allows to build a generic package. Most people want an optimized build, so my patch makes optimized one by default.

Comment 4 Marek Szuba archtester

2020-06-18 12:59:37 UTC

Personally, I really do not think darktable ebuilds should mess with this at all. It is up to the user to set their compiler flags the way THEY want! Will work on removing this logic soon.

Note to self: this affects all ebuilds we have in the tree, including the live one as of now.

Comment 5 Larry the Git Cow gentoo-dev

2020-06-18 16:30:38 UTC

The bug has been closed via the following commit(s):

https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=ba35b96b501f53471cc61bdc9d518b1f48d17ef7

commit ba35b96b501f53471cc61bdc9d518b1f48d17ef7
Author:     Marek Szuba <marecki@gentoo.org>
AuthorDate: 2020-06-18 16:26:54 +0000
Commit:     Marek Szuba <marecki@gentoo.org>
CommitDate: 2020-06-18 16:29:21 +0000

    media-gfx/darktable: prevent CMake from overriding march and mtune
    
    Closes: https://bugs.gentoo.org/692786
    Signed-off-by: Marek Szuba <marecki@gentoo.org>

 media-gfx/darktable/darktable-3.0.2-r1.ebuild      |  1 +
 ...darktable-3.0.2_cmake-march-autodetection.patch | 26 ++++++++++++++++++++++
 2 files changed, 27 insertions(+)