Bug 1421105

Summary:	Switch from Requires kernel-devel to kernel-devel-uname-r
Product:	[Fedora] Fedora	Reporter:	Nicolas Chauvet (kwizart) <kwizart>
Component:	systemtap	Assignee:	Frank Ch. Eigler <fche>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	26	CC:	brolley, dsmith, fche, jistone, lberk, mjw, samuel-rhbugs, scox, wcohen
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Hardware:	Unspecified
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Last Closed:	2017-12-08 10:27:37 UTC	Type:	Bug
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Embargoed:
Bug Depends On:
Bug Blocks:	1420754

Description Nicolas Chauvet (kwizart) 2017-02-10 11:03:22 UTC

Description of problem:
When installing the systemtap-devel package, there is a kernel-devel dependency.
But since any kernel-devel varriant (PAE/lpae/etc) has the kernel-devel virtual provide, it's not possible to prefer kernel-devel over kernel-debug-devel.

I sugguest to drop the kernel-devel virtual provide in the kernel package and to use the right virtual as kernel-devel-uname-r

Version-Release number of selected component (if applicable):
current version in devel

How reproducible:
dnf install systemtap-devel


Actual results:
kernel-devel-debug is installed (which might be right for systemtap, but not if using the regular kernel package)

Expected results:
it should install the kernel-devel matching the kernel (or at least the statistically best candidate).

Additional info:
see also rhbz#1420754

Comment 1 David Smith 2017-02-10 14:26:10 UTC

I think I see what you are trying to do here, and the 'kernel-devel-uname-r' virtual provide is certainly new to me.

Is this going to work in the case of: you've got the regular kernel installed and then install systemtap. That will pull in kernel-devel. You then install the debug kernel. Is the latter operation going to pull in kernel-debug-devel?

One more question. In what version of Fedora was kernel-devel-uname-r introduced? In what version of RHEL was it introduced?

Comment 2 Nicolas Chauvet (kwizart) 2017-02-10 17:17:19 UTC

Short answer no:

Moving to kernel-devel-uname-r only move to a virtual provide, over using a "not so much virtual" provide because it's also the name of a real-package.
Unfortunately this is not what will make it select kernel-devel as the preferred package.

In the current packaging (allowing weak dependencies), the current best method is described in the guideline, as real life example:
https://fedoraproject.org/wiki/Packaging:WeakDependencies
So that would ends to use 
Requires: kernel-devel-uname-r
%{fedora:Suggests: kernel-devel}
in RHEL cases, the behavior is still undetermined (or it will use a different rule, such as shorter names wins

kernel-devel-uname-r is supported down to el6/el7 kernels, I haven't checked el5 ones. All current fedora releases are supported.

The long term solution is probably to use boolean dependencies, and that's should fix the behavior to install the right kernel*devel varriant matching the kernel*. 
That been said, it will not check that the "version" are same...

Comment 3 David Smith 2017-02-10 20:08:04 UTC

Fixed upsteam in commit 19eace0:

<https://sourceware.org/git/gitweb.cgi?p=systemtap.git;a=commitdiff;h=19eace0c06aefa21604f5ba4a5d9781e359a07c3;hp=e239d05087dc7fff26d50a3b17bdf15d97e33662>

Comment 4 Fedora End Of Life 2017-02-28 11:14:36 UTC

This bug appears to have been reported against 'rawhide' during the Fedora 26 development cycle.
Changing version to '26'.

Comment 5 Nicolas Chauvet (kwizart) 2017-12-08 10:27:37 UTC

This change is available in current release.