Originally reported @ github.com/docker/compose/issues/5618

It seems that tarfile.itn() attempts to execute bitwise operations on a float if the n argument is a negative float, raising a TypeError.

As pointed out in the original report, this is an issue when converting some mtime values in TarInfo._create_header

This also happens for positive floats > 8**11 - 1, but that one is less of an issue for the next two hundred years or so.