-Wstrict-aliasing is flagging code that may break with compiler optimizations that -fstrict-aliasing unlocks

[jsetje]

When building a modern gcc and -O2 or higher which enables -fstrict-aliasing there are a number of these warnings:

 dereferencing type-punned pointer will break strict-aliasing rules

This is flagging code that may break with compiler optimizations that are unlocked by -fstrict-aliasing.

The short answer is to build with -fno-strict-aliasing which will disable both the optimizations and the warnings.

The longer answer may be to evaluate fixing the code to be safe for such optimizations.