2021 Deprecations

[mwichmann]

This thread is to discuss SCons components which could be deprecated in the near future - considering 2021 (maybe into early 2022) as the bound rather than any specific release/version.

1. Qt 3.x tool. See Status of Qt support in SCons #4018 (merged, this is now deprecated in 4.3)
2. os/2 platform. IBM support ended in 2006 (though has been continued by two outside companies, it hasn't actually evolved, and it's likely nobody could build a Python in the range supported by SCons which would run on os/2).
3. Per-directory sconsign files.

Already deprecated in 2021:

1. Python 3.5 support (in 4.2.0, dropped in 4.3)

[mwichmann]

Qt part submitted as #4052

[mwichmann]

Added: per-directory sconsign files. The manpage has long included this comment:

This is a backwards-compatibility meaure to support what was the default behavior prior to SCons 0.97 (i.e. before 2008). Use of this mode is discouraged and may be deprecated in a future SCons release.

A feature that was discouraged and backwards-compat even before the 1.0 release woul seem to be a candidate to start the deprecation cycle on, no?