kdump fails to start on arm64

[jeffdyoung]

Describe the bug

Following these steps to start kdump on arm64. The machine restarts, but kdump.service fail with this error:

Jul 18 14:44:21 ip-10-0-74-126 dracut[1198]: *** Squashing the files inside the initramfs ***
Jul 18 14:44:31 ip-10-0-74-126 dracut[1198]: *** Squashing the files inside the initramfs done ***
Jul 18 14:44:31 ip-10-0-74-126 dracut[1198]: *** Creating image file '/var/lib/kdump/initramfs-6.3.8-200.fc38.aarch64kdump.img' ***
Jul 18 14:44:31 ip-10-0-74-126 dracut[1198]: *** Creating initramfs image file '/var/lib/kdump/initramfs-6.3.8-200.fc38.aarch64kdump.img' done ***
Jul 18 14:44:32 ip-10-0-74-126 kdumpctl[4638]: sed: -e expression #1, char 14: unknown command: `/'
Jul 18 14:44:32 ip-10-0-74-126 kdumpctl[807]: kdump: kexec: failed to load kdump kernel
Jul 18 14:44:32 ip-10-0-74-126 kdumpctl[807]: kdump: Starting kdump: [FAILED]

Reproduction steps

1. sudo rpm-ostree kargs --append='crashkernel=300M'
2. sudo systemctl enable kdump.service
3. sudo systemctl reboot
4. after the reboot check kdump.service

Expected behavior

kdump.service should run, and a user should be able to generate a vmcore dump with echo c > /proc/sysrq-trigger

Actual behavior

kdump fails to start.

System details

• AWS ARM64 t4g.medium
• ami-03777816913e8e8a6

Butane or Ignition config

n/a, manually setup kdump

Additional information

No response

[dustymabe]

I think this is a duplicate of #1430 though the sed error looks new.

TL;DR kexec doesn't work yet on 6.2+ kernels.

[dustymabe]

Closing as a duplicate of #1430