Notes for vtk9 - reproducible builds result

Version annotated: 9.0.1+dfsg1-3
Identified issues:
Identifier: diffoscope_runs_forever
Description Some packages cannot be analysed by diffoscope due to it running "forever".
Currently the diffoscope process is killed after 120 minutes. collects a list of currently
undiffable packages (as well as other issues with
Identifier: nondeterministic_ordering_in_documentation_generated_by_doxygen
Description "Additional Inherited Members" has nondeterministic children in the (HTML?)
This can also happen when there is a real C function and a hash-define with
the same name. Doxygen sorts the member names but it only appears to use
the name so it is not stable relative to their type, resulting in
nondeterministic output.
MemberNameSDict::compareValues in doxygen's membername.cpp is suspicious.
Identifier: captures_build_arch
Description Captures the build arch (`uname -m`, typically i686 v. x86_64).
Comments: Diffoscope sometimes completes when run against bullseye, so
possibly build-path related differences generate a huge amount of
output (e.g. image files).
Includes build log containing timestamp and other
non-deterministic information in _formulas.log in documentation
Build architecture captured with CMAKE_SYSTEM_PROCESSOR.

Our notes about issues affecting packages are stored in notes.git and are targeted at packages in Debian in 'unstable/amd64' (unless they say otherwise).