I haven't tried deploying a unikernel in production yet - I've been mostly using/debugging only OCaml code on Linux in production - but it should be possible to implement the kind of logging you describe.
For example I've seen a project that would collect&dump its log ring-buffer when an exception was encountered in a unikernel, or one that collects very detailed profiling information from a unikernel.
It would be nice to have some kind of a "shell" to inspect details about the application when something goes wrong, but that applies equally to non-unikernel applications.
The difference is that with unikernels the debugging tool would be provided as a library, whereas with traditional applications debugging is provided as a language-independent OS tool.
It would be nice to have some kind of a "shell" to inspect details about the application when something goes wrong, but that applies equally to non-unikernel applications. The difference is that with unikernels the debugging tool would be provided as a library, whereas with traditional applications debugging is provided as a language-independent OS tool.