Zephyr/nordicnrf52 build fails when using CONFIG_USERSPACE

[RobMeades]

Originally raised in community issue 32061, not sure whether to raise it here or under Zephyr, but since Nordic's main framework is Zephyr, and the problem occurred on the Nordic platform, I thought I'd raise it here.

We set CONFIG_USERSPACE=y in our Zephyr/Nordic NRF52 builds (in order to be more likely to trap stack overruns); this works fine in the native Zephyr/NRFConnect world. We now want to do the same build under PlatformIO.

However, whatever version of nordicnrf52 we select (we've tried all the recent ones, 9.x.y back to 8.3.0 (board nrf52840_dk)), when CONFIG_USERSPACE=y is set the build fails because the underlying Zephyr CMakeLists.txt boilerplate does not create the generated file linker-kobject-prebuilt-rodata.h, leading to a linker failure. This works fine when we build natively under Zephyr/NRFConnect (with the the same version of Zephyr, version 2.7). If we set CONFIG_USERSPACE=n then the build completes fine.

We've tried this building under Windows, building under Linux, and with a few different versions of Python and it is quite consistent.

Any clues as to what we might be doing wrong?