So, there was a post by Justine Tunney about her port of OpenBSD’s pledge() to her own libc, the Cosmopolitan libc. She is also calling out that previous attempts at this were flawed: There’s been a few devs in the past who’ve tried this. I’m not going to name names, because most of these projects were never completed. […] The projects that got further along also had oversights like allowing the changing of setuid/setgid/sticky bits. So none of the current alternatives should be use...