#3615 PR merged: Error out when KERNEL_VERSION is not set

Labels: fixed / solved / done, minor bug

jsmeix opened issue at 2026-07-09 08:22:

For me it Errors out for those wrong settings in local.conf

KERNEL_VERSION=''
KERNEL_VERSION=' '
KERNEL_VERSION='foo bar'
unset KERNEL_VERSION
  • Description of the changes in this pull request:

In build/GNU/Linux/400_copy_modules.sh
KERNEL_VERSION must be set.
It is set in default.conf to $( uname -r )
if not set by the user via the '-r' option of sbin/rear
so if it is not set it is likely an error by the user
(e.g. empty setting in local.conf).
If we set it to $( uname -r ) if not set,
we would falsely hide an error, cf.
"In case of errors better abort than to blindly proceed" in
https://github.com/rear/rear/wiki/Coding-Style

So we Error out now, see
https://github.com/rear/rear/pull/3614#discussion_r3528343520

But now the test is moved from
build/GNU/Linux/400_copy_modules.sh
to
prep/GNU/Linux/400_guess_kernel.sh
because this is the first script that uses KERNEL_VERSION
and the test now ensures KERNEL_VERSION is
a single non empty and non blank word.

codacy-production commented at 2026-07-09 08:24:

Up to standards ✅

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jsmeix commented at 2026-07-09 08:48:

Testing with the test

test "$KERNEL_VERSION" || Error "KERNEL_VERSION must be set"

in build/GNU/Linux/400_copy_modules.sh

With KERNEL_VERSION='' in local.conf I get

# usr/sbin/rear -D mkrescue
...
ERROR: FindStorageDrivers called but STORAGE_DRIVERS is empty and no builtin storage modules found
Some latest log messages since the last called script 260_storage_drivers.sh:
  2026-07-09 10:35:57.401225807 Entering debugscript mode via 'set -x'.
  2026-07-09 10:35:57.409746500 Trusted sourcing '/root/rear.github.master/usr/share/rear/rescue/GNU/Linux/260_storage_drivers.sh'
  grep: /lib/modules//modules.builtin: No such file or directory

With KERNEL_VERSION=' ' in local.conf I get

# usr/sbin/rear -D mkrescue
...
No kernel found in /boot that matches KERNEL_VERSION ' '
ERROR: Cannot autodetect what to use as KERNEL_FILE, you have to manually specify it in /root/rear.github.master/etc/rear/local.conf
Some latest log messages since the last called script 400_guess_kernel.sh:
  2026-07-09 10:35:22.860001867 Entering debugscript mode via 'set -x'.
  2026-07-09 10:35:22.868958732 Trusted sourcing '/root/rear.github.master/usr/share/rear/prep/GNU/Linux/400_guess_kernel.sh'
  2026-07-09 10:35:22.878055101 No kernel file '/boot/vmlinux- ' found
  2026-07-09 10:35:23.694687290 No kernel found in /boot that matches KERNEL_VERSION ' '

Where KERNEL_VERSION appears in the code:

# find usr/sbin/rear usr/share/rear/ -type f | xargs grep -l 'KERNEL_VERSION'

usr/sbin/rear
usr/share/rear/conf/default.conf
usr/share/rear/finalize/Fedora/550_rebuild_initramfs.sh
usr/share/rear/prep/GNU/Linux/400_guess_kernel.sh
usr/share/rear/rescue/GNU/Linux/240_kernel_modules.sh
usr/share/rear/rescue/GNU/Linux/260_collect_initrd_modules.sh
usr/share/rear/rescue/GNU/Linux/230_storage_and_network_modules.sh
usr/share/rear/lib/help-workflow.sh
usr/share/rear/lib/linux-functions.sh
usr/share/rear/lib/bootloader-functions.sh
usr/share/rear/build/GNU/Linux/400_copy_modules.sh
usr/share/rear/output/USB/Linux-i386/300_create_extlinux.sh

So for 'rear mkrescue'
prep/GNU/Linux/400_guess_kernel.sh
is the first script that uses KERNEL_VERSION

For 'rear recover'
finalize/Fedora/550_rebuild_initramfs.sh
only mentions KERNEL_VERSION in a comment
so KERNEL_VERSION is not used for 'rear recover'.

I will move the test from
build/GNU/Linux/400_copy_modules.sh
to
prep/GNU/Linux/400_guess_kernel.sh
and
ensure KERNEL_VERSION is a single non empty and non blank word.

jsmeix commented at 2026-07-09 10:15:

@rear/contributors
provided no objections appear
I would like to merge it tomorrow afternoon.

[Export of Github issue for rear/rear.]