loeg says, "programs rely on this". Guarantee or not, it constrains whether something is usable as a drop-in replacement interpreter, especially if people can'

loeg says, "programs rely on this". Guarantee or not, it constrains whether something is usable as a drop-in replacement interpreter, especially if people can't tell which programs will break, and doubly so if the breakage is a subtle data corruption race that doesn't show up in tests.