Crash from runaway recursion in a subquery-bodied function

[philrz]

The following crashes with a fatal error: stack overflow rather than returning the error value described in the docs.

$ super -version &&
  super -s -c "
fn rec(n): (values n | values rec(this+1))
values rec(1)"

Version: v0.3.0-357-g0c71fac6a

runtime: goroutine stack exceeds 1000000000-byte limit
runtime: sp=0x1ea707b804d8 stack=[0x1ea707b80000, 0x1ea727b80000]
fatal error: stack overflow

runtime stack:
runtime.throw({0xbdf3d5e?, 0x0?})
	/usr/local/opt/go/libexec/src/runtime/panic.go:1243 +0x48 fp=0x700005a8be28 sp=0x700005a8bdf8 pc=0xa4ac528
runtime.newstack()
	/usr/local/opt/go/libexec/src/runtime/stack.go:1207 +0x5dd fp=0x700005a8bf58 sp=0x700005a8be28 pc=0xa48b3fd
runtime.morestack()
	/usr/local/opt/go/libexec/src/runtime/asm_amd64.s:650 +0x7b fp=0x700005a8bf60 sp=0x700005a8bf58 pc=0xa4b285b
...

On my Intel Macbook, this ran for ~43 seconds and consumed ~1.5 GB of RAM before the crash.

Details

Repro is with super commit 0c71fac.

The error value is returned if the function body is a plain expression rather than a subquery:

$ super -s -c "
fn rec(n): rec(n+1)
values rec(1)"
error("stack overflow in function \"rec\"")

When using Claude to craft the simplified repro, it also gave its take on the root cause, which I've captured in a Gist.