That's in Debian 11 and later. That man page said something entirely different in Debian 10 and earlier, when they shipped glibc's libcrypt. Now they ship libxcrypt instead.
Fedora asked libxcrypt to give them back glibc's behavior, returning NULL, and they obliged by adding ./configure --disable-failure-tokens. But it's an option that Debian never enabled.
Fedora asked libxcrypt to give them back glibc's behavior, returning NULL, and they obliged by adding ./configure --disable-failure-tokens. But it's an option that Debian never enabled.
https://github.com/besser82/libxcrypt/issues/25
https://salsa.debian.org/md/libxcrypt/-/blob/master/debian/r...