libdevmapper/device mapper driver can return semi-random failures when
opening verity devices, and we have fallback code to deal with it.
But the test was not expecting the fallback path, so it became unreliable.
Fixes https://github.com/systemd/systemd/issues/23866
While I had tested that a symlink to /dev/null works to "mask" a sysext
I must have gotten something wrong and thus the instructions in
519c2f0d6b don't work. What works,
at least at the moment, is to instead have an empty directory with the
extension name under /etc/extensions/.
Correct the info in the man page and add a test for it.
When an extension image has binaries they should match the host
architecture. Currently there is no way to specify this requirement.
Introduce an ARCHITECTURE field in the extension's release file that
may be set to prevent loading on the wrong host architecture.
Since this new field is introduced late, we don't want to make
specifying it mandatory as it would break existing sysext images.
See https://github.com/systemd/systemd/issues/24061
A sysext image that merely contains static binaries has no dependency
on the host distribution and should be able to be used anywhere.
Support the special '_any' value for the ID field in the extension to
opt-out of ID and VERSION_ID/SYSEXT_LEVEL matching.
See https://github.com/systemd/systemd/issues/24061
