[SOLVED]Can't boot after enabling "savedconfig" USE flag

[amirz]

OK... I think I know exactly what happened now.
in the wiki the instruction is missing an important part and that is to first copy the default savedconfig file and then change it with menuconfig. As the whole reason of using savedconfig flag is only to tweak small number of options (right?) I think it's appropriate to use the current config as the base.

portage system also acted very strange.
first of all I was expecting that when I delete the savedconfig use flag it would replace the savedconfig file for me but it didn't and just left me with a broken config file.
second, I assumed when I rebuild the kernel it should just delete the old modules directory and make a new one but no, it only installed the new modules and didn't delete the old ones. this looks like a bug to me but maybe there is a reason for this behavior? idk...

after deleting the modules directory everything went back to normal. after building gentoo-kernel I get a message telling me that it did in fact use the savedconfig file. before deleting the modules directory it didn't print it.

thank you zen_desu for your help and also for your awesome initrd tool )
I'll mark this as solved now.

[zen_desu]

OK... I think I know exactly what happened now.
in the wiki the instruction is missing an important part and that is to first copy the default savedconfig file and then change it with menuconfig. As the whole reason of using savedconfig flag is only to tweak small number of options (right?) I think it's appropriate to use the current config as the base.

portage system also acted very strange.
first of all I was expecting that when I delete the savedconfig use flag it would replace the savedconfig file for me but it didn't and just left me with a broken config file.
second, I assumed when I rebuild the kernel it should just delete the old modules directory and make a new one but no, it only installed the new modules and didn't delete the old ones. this looks like a bug to me but maybe there is a reason for this behavior? idk...

after deleting the modules directory everything went back to normal. after building gentoo-kernel I get a message telling me that it did in fact use the savedconfig file. before deleting the modules directory it didn't print it.

thank you zen_desu for your help and also for your awesome initrd tool )
I'll mark this as solved now.

I'm happy to help.

You hit an interesting bug, because by design I think the install process on gentoo does not clear this dir. I'm not 100% sure why but it may be related to out of tree modules like nvidia and zfs.

In general, it would probably not make sense to clear out the modules dir, but in cases where you remove modules, it will render the remaining module useless even though it exists. I believe depmod looks at all module files and doesn't actually consider if the target kernel supports that module (probably because the module dir is not even required to have a symlink to the related kernel)

[sam_]

Right now, depcleaning a kernel leaves the system bootable because it doesn't touch /boot and it doesn't touch /lib/modules. Dropping the entries from UNINSTALL_IGNORE would make it do the latter (I think files in /boot are installed as orphaned so they'd be fine either way).

I don't know what to do about a scenario like was hit here. We could maybe warn on it but it would need to be done with care.