deal.ii: sundials2 not found during configure; needs sundials instead?

[mascguy (Christopher Nielsen)]

This port currently declares a dependency on sundials2, but it appears that it requires a newer version - suggesting that sundials (which is v5.8.x) is necessary instead:

--   SUNDIALS_VERSION: 0.0.0
--   SUNDIALS_LIBRARIES: /opt/local/lib/libsundials_idas.dylib;/opt/local/lib/libsundials_arkode.dylib;/opt/local/lib/libsundials_kinsol.dylib;/opt/local/lib/libsundials_nvecserial.dylib
--   SUNDIALS_INCLUDE_DIRS: *** Required variable "SUNDIALS_INCLUDE_DIR" set to NOTFOUND ***
--   SUNDIALS_USER_INCLUDE_DIRS: *** Required variable "SUNDIALS_INCLUDE_DIR" set to NOTFOUND ***
-- Could NOT find SUNDIALS
-- Could not find a sufficient Sundials installation: deal.II requires at least version 3.0.0, but version 0.0.0 was found.
-- DEAL_II_WITH_SUNDIALS has unmet external dependencies.

Switching to sundials, the configure phase does succeed:

--   SUNDIALS_VERSION: 5.8.0
--   SUNDIALS_LIBRARIES: /opt/local/lib/libsundials_idas.dylib;/opt/local/lib/libsundials_arkode.dylib;/opt/local/lib/libsundials_kinsol.dylib;/opt/local/lib/libsundials_nvecserial.dylib
--   SUNDIALS_INCLUDE_DIRS: /opt/local/include
--   SUNDIALS_USER_INCLUDE_DIRS: /opt/local/include
-- Found SUNDIALS
-- DEAL_II_WITH_SUNDIALS successfully set up with external dependencies.

However, the overall build still fails, due to issue:56106