file works with libpthread, but when built into libc_r which has a non-weak
symbol of the same name, the linker behaves unpredicatably and sometimes
links the wrong symbol. The linker behaviour is a byproduct of what
the program calls from object to object so it is like winning a lottery
if the program actually works. The odds are quite good - 95:1, I think.
We need a sure thing, though, so weak symbols can't be used instead
of renaming things.
cf6229a854