Arch Linux

The new glibc in [testing] repository drops libcrypt.h header and corresponding
static library. The upstream plans to eventually remove libcrypt from glibc tree
in favor of a separate project libxcrypt; it's now available in [testing].

There's no breakage (famous last words) as glibc still ships libcrypt.so.1 for
backwards compatibility, while libxcrypt package provides development headers
and library with bumped soname version due to removal of the functions
providing insecure hashes. You may need to add '#include <crypt.h>' if it was
missing before as uninstd.h no longer provides a declaration of the crypt
function.

Packages go to [testing] until the toolchain is moved to [core].