build_sysext uses a base squashfs (basically a full snapshot of the
Flatcar OS image) to build custom sysexts on top. Before building it
ensures the base image actualy matches the OS version in the repository
root.
The version string includes a BUILD_ID which might be auto-generated (by
including common.sh) if it is not present in the version file - e.g.
when the version is an official release (tag). This build ID
auto-generation causes issues with the version check when image build
and sysext build scripts run independently - each will generate its own
build ID, and this will cause build_sysext's version check to fail.
build_sysext will now use the build id from the base squashfs when it is
not set in the source tree's version.txt to work around that issue. This
is a more general solution than 361eda220b368c3c3a959357c54db10d4c2f1d1a
(which this patch reverts) as it directly addresses the issue in
build_sysext instead of working around it in sysext_prod_builder.
Signed-off-by: Thilo Fromm <thilofromm@microsoft.com>
1b7c0c2ecc