Recently, 2024-10-31, macOS arm64 DEBUG runs of base_test began failing consistently.

This does not appear to be caused by any code changes, but something in the target machines or test environment. Regardless, we have to figure it out.

in StringDataTest, the failing test is a DEATH_TEST that checks that a StringData constructed with a nullptr and nonzero length will hit an invariant in debug builds, named StringDataDeathTest/InvariantNullRequiresEmpty.

For some reason, the DEATH_TEST child process does not produce any output. But it still seems to die, because the parent process reacts to its death.

So we need to figure out how it died and what happened to its output stream.