A new SCons release, 4.5.1, is now available on the SCons download page:
https://scons.org/pages/download.html
Here is a summary of the changes since 4.5.0:
FIXES
Fix a problem in 4.5.0 where using something like the following code will cause a Clone()'d environment to share the CPPDEFINES with the original Environment() which was cloned. Causing leakage of changes to CPPDEFINES when they should be completely independent after the Clone.
env=Environment(CPPDEFINES=['a']) env.Append(CPPDEFINES=['b']) (or AppendUnique,Prepend,PrependUnique) env1=env.Clone() env1.Append(CPPDEFINES=['c']) (or any other modification, but not overwriting CPPDEFINES)
Now env['CPPDEFINES'] will contain 'c' when it should not.
Thanks to the following contributors listed below for their contributions to this release.
git shortlog --no-merges -ns 4.5.0..HEAD
3 William Deegan
1 Mats Wichmann