I can’t seem to find a definitive answer for all POSIX platforms. But for all the ones that PyPy currently supports, I think the answer is true. So if you want to make the changes then I think it’s a reasonable assumption and a good idea.

I still have no
clue why all our tests still pass on OS/X

I think it’s because `rpython.translator.platform.Platform._finish_linking` function doesn’t include `so_prefixes` on the platform in the first place, so for tests like `test_lib_on_libpaths` will generate a shared library called `c_file.dylib`. Then in `get_ctypes_callable` function it prepends the library name with the currently empty prefix on Darwin platform, it can find the shared library file with the constructed absolute path. So the proposed fix will still work because it includes both ‘lib’ and empty prefix.

On the other hand, I wonder if it’s also reasonable to modify the `_finish_linking` function to include `platform.so_prefix[0]` to the generated shared library name (see the attached patch).

Regards,

John Zhang