stacker is:

A library to help grow the stack when it runs out of space.

This is an implementation of manually instrumented segmented stacks where points in a program's control flow are annotated with "maybe grow the stack here". Each point of annotation indicates how far away from the end of the stack it's allowed to be, plus the amount of stack to allocate if it does reach the end.

Once a program has reached the end of its stack, a temporary stack on the heap is allocated and is switched to for the duration of a closure.

Recent PRs that might be relevant: #41625 (MIR inlining) and #41676 (macro expansion).

Also related: #40161, a meta issue for places where deep recursion arise.

cc @rust-lang/compiler