kpatch-build fails on Fedora 42: cannot find kernel source directory

[oshoval]

Problem

kpatch-build on Fedora 42 fails when extracting kernel source from the SRPM. The mv glob at the source-finding step doesn't match, and die is called with the generic message:

ERROR: kpatch build failed

The build log shows mv failing because the glob BUILD/kernel-*/linux-* doesn't match the Fedora 42 directory layout.

Cause

Starting with Fedora 42, the kernel SRPM unpacks with an extra level of nesting:

BUILD/kernel-6.14.0-build/kernel-6.14/linux-6.14.0-63.fc42.x86_64/

The existing glob BUILD/kernel-*/linux-* only matches the traditional flat layout used by Fedora < 42, RHEL, and CentOS:

BUILD/kernel-6.12.0/linux-6.12.0-100.fc41.x86_64/

Environment

• Fedora 42 (kernel 6.14.0-63.fc42.x86_64)
• kpatch master (7552b46)

Fix

#1496

---

Co-assisted by Claude (Anthropic).

[joe-lawrence]

Hi @oshoval, thanks for opening the issue and the MR fix -- however, Fedora's kernel config is no longer supported by kpatch-build due to CONFIG_X86_KERNEL_IBT. (See #1411). Since the design of kpatch-build makes it inherently difficult to support, much like clang's thinLTO, a new in-kernel-tree tool called klp-build was created to address problems like this. So unfortunately I don't think kpatch-build will ever support modern Fedora / RHEL-10+ configs.

[oshoval]

Hi Joe, thanks

Locally fwiw i compiled with CONFIG_X86_KERNEL_IBT disabled indeed, so wondering if it will be good to support this ?
Moreover having the logic of finding the path regardless the distro might have value ?
But i understand its better to keep it simple, and focused for what is supported and tested.

Thanks for considering