Commits
351d12437 ("nixos/release-notes: PHP config-file-scan-dir /etc -> /etc/php.d")
41c8aa8d6 ("php: change config-file-scan-dir from /etc to /etc/php.d")
were merged to master _after_ NixOS 16.09. Commit 351d12437 then wrongly
updated the NixSO 16.09 release notes. Fix by moving the entry to NixOS
17.03.
To build the manual, you need Nix installed on your system (no need
for NixOS). To install Nix, follow the instructions at
https://nixos.org/nix/download.html
When you have Nix on your system, in the root directory of the project
(i.e., `nixpkgs`), run:
nix-build nixos/release.nix -A manual.x86_64-linux
When this command successfully finishes, it will tell you where the
manual got generated.