New hardening in 3.50.0: "Immutable Sticky Bit" where Syd enforces the immutability of the sticky bit at chmod(2) boundary for directories. Sticky bit on dirs such as /tmp is a critical security primitive that restricts file deletion/renaming to file/directory owner or root. This also helps raise the bar for trusted symlink bypasses. On by default, disable with trace/allow_unsafe_sticky:1. Refer to the manual page for more information: https://man.exherbo.org/syd.7.html#Immutable_Sticky_Bit