Code that assumes time_t is the same width as int is already broken, and won't work on typical 64-bit systems were int is 32 bits and time_t is 64 bits.
In any case, I'm not sure I've ever seen any such code.
In any case, I'm not sure I've ever seen any such code.
You missed the point. It is meant that code _built for the same target_ "assumes" all instances use the same definition of time_t, and not about such a guarantee across different targets. That's why Gentoo solution to redefine target is cumbersome but finally working - as radical as axe.