v3.5.9.

New features

• Type hints in rpy2 are now checked with mypy.

Bugs fixed

• Building the path to the R shared library was incorrectly
  using the output of R CMD config LIBnn (issue #982).

• R started raising warnings when calling formals on SPECIALSXP R objects.
  Internal functions rpy.robjects.functions calling formals no longer
  propagate the warnings.

• The numpy converter was not turning NA_character_ into
  None (issue #979).

• rpy2.situation included an eager import rpy2 that could cause a version
  mismatch error with some build/install toolchain (issue #984). The import is now
  lazy/delayed.

• Installation targets pandas, all, and test now specify pandas>=1.2.0
  (which should limit frequencies of issues like #998).

Changes

• rpy2.robjects.conversion.Converter objects are no longer functioning context
  managers. An exception is now raised when trying to use it that way.
  The feature was introduced with rpy2-3.5.7 but it does not guarantee the locality
  of a context manager and can result in permanently changed conversion rules.
  The method rpy2.robjects.conversion.Converter.context should be used instead.