Both of these systems have /dev/ptmx for creating pseudoterminals.
OS X Leopard (10.5) added it in 2007, and Linux has had support for
it since v2.1 (1998).
This fixes a bug with pseudoterminal creation on Linux and macOS
where a new pseudoterminal cannot be created because the wrong
method is being used to find one.
Both of these systems have /dev/ptmx for creating pseudoterminals. OS X Leopard (10.5) added it in 2007, and Linux has had support for it since v2.1 (1998).
This fixes a bug with pseudoterminal creation on Linux and macOS where a new pseudoterminal cannot be created because the wrong method is being used to find one.