SConstruct - build fails on old gcc

$ gcc --version
gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-44)
...
cc1: warnings being treated as errors
src/cm_quantile.c: In function 'cm_insert':
src/cm_quantile.c:254: warning: dereferencing type-punned pointer will break strict-aliasing rules
src/cm_quantile.c:274: warning: dereferencing type-punned pointer will break strict-aliasing rules
src/cm_quantile.c:275: warning: dereferencing type-punned pointer will break strict-aliasing rules
src/cm_quantile.c:293: warning: dereferencing type-punned pointer will break strict-aliasing rules
src/cm_quantile.c:294: warning: dereferencing type-punned pointer will break strict-aliasing rules