Still, it's a little weird that it only prints to file descriptor 2 (hard-wired), if STDERR is closed.
Uhm, the kernel itself doesn't know anything about stderr. It's a convention used by utilities. And the convention is, "file descriptor 2 is stderr". (Just as file descriptor 1 is stdout, and file descriptor 0 is stdin).

Making the file descriptor variable would break many things, not in the least the expectation of users.

In reply to Re^3: Using warn() when STDERR is closed by JavaFan
in thread Using warn() when STDERR is closed by akeyes

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