  A new SCons checkpoint release, 3.1.2, is now available
  on the SCons download page:

          https://scons.org/pages/download.html

  Here is a summary of the changes since 3.1.1:

  NOTE: The 4.0.0 Release of SCons will drop Python 2.7 Support

  NEW FUNCTIONALITY
    - Added debug option "action_timestamps" which outputs to stdout the absolute start and end time for each target.

  REMOVED FUNCTIONALITY
    - Turn previously deprecated debug options into failures:
      --debug=tree, --debug=dtree, --debug=stree, --debug=nomemoizer.
    - Remove deprecated SourceSignatures, TargetSignatures
    - Remove deprecated Builder keywords: overrides and scanner
    - Remove deprecated env.Copy
    - Remove deprecated BuildDir plus SConscript keyword build_dir


  CHANGED/ENHANCED EXISTING FUNCTIONALITY
    - Update Command() function to accept target_scanner, source_factory, and target_factory arguments.
      This makes Command act more like a one-off builder.
    - Added support for "-imacros" to ParseFlags
    - EXPERIMENTAL NEW FEATURE: Enable caching MSVC configuration
      If SCONS_CACHE_MSVC_CONFIG shell environment variable is set,
      SCons will cache the results of past calls to vcvarsall.bat to
      a file; integrates with existing memoizing of such vars.
      On vs2019 saves 5+ seconds per SCons invocation, which really
      helps test suite runs.

  FIXES
    - Fix suncxx tool (Oracle Studio compiler) when using Python 3.  Previously would throw an exception.
      Resolved by properly handling tool version string output as unicode.
    - Resolved a race condition in multithreaded Windows builds with Python 2
      in the case where a child process is spawned while a Python action has a
      file open. Original author: Ryan Beasley.
    - Fix CheckFunc detection code for Visual 2019. Some functions
      (e.g. memmove) were incorrectly recognized as not available.
    - Fix stacktrace when using SCons with Python 3.5+ and SunOS/Solaris related tools.
    - Latex: Avoid crash with UnicodeDecodeError on Python 3 when a Latex log file in
      non-UTF-8 encoding (e.g. containing umlauts in Latin-1 encoding when
      the fontenc package is included with \usepackage[T1]{fontenc}) is read.
    - CmdStringHolder fix from issue #3428

  IMPROVEMENTS
    - Improved threading performance by ensuring NodeInfo is shared
      across threads. Results in ~13% improvement for parallel builds
      (-j# > 1) with many shared nodes.
    - Improve performance of Entry.disambiguate() by making check for
      most common case first, preventing unnecessary IO.
    - Improved DAG walk performance by reducing unnecessary work when
      there are no un-visited children.


  PACKAGING

     - N/A

  DOCUMENTATION

    -  N/A

  DEVELOPMENT

    - N/A


Thanks to the following developers for their contributions to this release.
git shortlog --no-merges -ns 3.1.1..HEAD
    59  Mats Wichmann
    21  William Deegan
     8  Edoardo Bezzeccheri
     5  Adam Gross
     5  maiphi
     4  Ivan Kravets
     4  Mathew Robinson
     2  Jakub Kulík
     2  Jacek Kuczera
     2  Rob Boehne
     2  Jason Kenny
     2  Tim Gates
     1  Jakub Kulik
     1  Theogen Ratkin
     1  jw0k


