Golang has a feature that I love in general but that makes it very easy to keep unintended allocations around. If you have a struct with a simple int field, and you store that somewhere as an *int, the entire struct and anything it points to will be kept alive. This is super useful for short-lived pointers, and super dangerous for long-lived pointers.

Most other widely used GCed languages don’t allow the use of arbitrary interior pointers (though most GCs can actually handle them at the register level).