xsel 1.2.0 does not build on macOS Monterey. The error is: ``` xsel.c:372:14: error: 'fork' is deprecated: Use posix_spawn or fork [-Werror,-Wdeprecated-declarations] if ((pid = fork()) == -1) { ^ ``` This was reported to MacPorts [here](https://trac.macports.org/ticket/63748).