Error updating e2fsprogs 1 40 8 gentoo
Gentoo is a fast, modern meta-distribution with a clean and flexible design.It is built on an ecosystem of free software and does not hide what is beneath the hood from its users.Handbook: Parts is a meta handbook used for transcluding text.Use the architecture-specific Handbooks found in the Handbook list. You are about to enter the world of choices and performance. When installing Gentoo, this is made clear several times - users can choose how much they want to compile themselves, how to install Gentoo, what system logger to use, etc.Hence the configuration file of the new kernel may have new entries the configuration file of the old kernel doesn't have, and it might not have entries anymore which are present in the configuration file of the old kernel.
Making a new kernel from the new sources is basically the same process as making a kernel when installing the system.A new kernel may have options or features the old kernel does not have, or it might not have a feature or option anymore which the old kernel still has.The kernel configuration specifies whether the features and options of a kernel are to be enabled or not, perhaps built into the kernel, or perhaps built as modules which can be loaded into the running kernel on demand.Also, to avoid too many surprises, you might find it helpful to subscribe to one of the mailing lists like (WARNING: ~100 mails a day on this list) since pretty much any major update issues are likely to show up on the list with plenty of discussion explaining how to solve them.I would guess that the next major "problem" update will be the migration to openrc once it goes stable (it was done on ~arch middle of last year iirc with only a few issues, primarily with networking changes).