Kernels with modules cannot be `pmbootstrap install`ed (downstream only?)

Describe your issue

What's the expected behaviour?

Linux packages that do make modules_install should be pmbootstrap installable.

What's the current behaviour?

pmbootstrap install for samsung-a5y17lte or samsung-goyawifi fails with:

...
19:03:05.085653 - Searching for kernel modules from /usr/share/mkinitfs/modules
19:03:05.085961 -- Including modules from: /usr/share/mkinitfs/modules/00-default.modules
19:03:05.086976 unable to process module list file "/usr/share/mkinitfs/modules/00-default.modules": unable to get module file "aes": kernel module.dep not found: /lib/modules/3.18.14
19:03:05.087193 failed to generate:  initramfs
19:03:05.087733 mkinitfs completed in: 0.03s
ERROR: postmarketos-mkinitfs-2.6.1-r0.trigger: script exited with error 1

How to reproduce your issue?

pmbootstrap init and chose samsung-a5y17lte, and then pmbootstrap install

What device are you using?

samsung-a5y17lte or samsung-goyawifi

On what postmarketOS version did you encounter the issue?

• edge (master branch)

• v24.06

• v24.12

• I confirm that the issue still is present after running sudo apk upgrade -a

On what environment did you encounter the issue?

Environments

• GNOME Shell on Mobile
• Phosh
• Plasma Mobile
• Sxmo (Wayland/Sway) Please post the output of sxmo_version.sh
• Other: Doesn't matter

How did you get postmarketOS image?

• from https://images.postmarketos.org
• I built it using pmbootstrap
• It was preinstalled on my device

What's the build date of the image? (in yyyy-mm-dd format)

Additional information

linux-samsung-a5y17lte is based on linux 3.18. The kernel supports loadable modules, but all drivers are built as built-in. The device porter (@dsankouski) has added an out-of-source module qcacld. Another example is samsung-goyawifi where only a few drivers are built as modules, and the aes module is hence not found.

Normally, without modules, postmarketos-mkinitfs reports:

20:41:58.376771 - Searching for hook scripts from /etc/mkinitfs/hooks
20:41:58.378303 -- kernel module directory not found: "/lib/modules/3.18.140", not including modules
20:41:58.378698 -- kernel module directory not found: "/lib/modules/3.18.140", not including modules
20:41:59.159530 initramfs completed in: 0.81s

but when /lib/modules/* is present it instead fails with the error as above:

19:03:05.085653 - Searching for kernel modules from /usr/share/mkinitfs/modules
19:03:05.085961 -- Including modules from: /usr/share/mkinitfs/modules/00-default.modules
19:03:05.086976 unable to process module list file "/usr/share/mkinitfs/modules/00-default.modules": unable to get module file "aes": kernel module.dep not found: /lib/modules/3.18.14
19:03:05.087193 failed to generate:  initramfs
19:03:05.087733 mkinitfs completed in: 0.03s
ERROR: postmarketos-mkinitfs-2.6.1-r0.trigger: script exited with error 1

This seems to be a regression that happened at some point in the last three years (last time linux-samsung-a5y17lte was rebuilt).

Issue was reported on matrix by rican.