It appears that some kernel modules required by charon/StrongSwan are no longer part of the default raspi-kernel. They are now part of a separate package "linux-modules-extra-raspi". Installing this package allowed my installation of StrongSwan to work unter Ubuntu 21.10.
I found this out by taking a look on other bug reports concerning linux-raspi, especially this one about docker:
It appears that some kernel modules required by charon/StrongSwan are no longer part of the default raspi-kernel. They are now part of a separate package "linux- modules- extra-raspi" . Installing this package allowed my installation of StrongSwan to work unter Ubuntu 21.10.
I found this out by taking a look on other bug reports concerning linux-raspi, especially this one about docker:
https:/ /bugs.launchpad .net/ubuntu/ +source/ linux-raspi/ +bug/1947601