MANPATH includes some unwanted entries in the front on macOS

[iawaknahc]

MANPATH includes some unwanted entries in the front on macOS, namely /usr/share/man and /usr/local/share/man, as shown in the image below.

This will confuse manpath(1), as shown below.

# Running this in ghostty

$ manpath
.manpath-wrapped: warning: $MANPATH set, appending /nix/store/a34dn9y67ywc3bzw2l33k6400smhjn32-man-db-2.13.0/etc/man_db.conf
/usr/share/man:/usr/local/share/man:/Applications/Ghostty.app/Contents/Resources/ghostty/../man:/Users/me/.nix-profile/share/man:/nix/var/nix/profiles/default/share/man:/System/Cryptexes/App/usr/share/man:/usr/share/man

$ man -aw man
/usr/share/man/man1/man.1
/nix/store/a34dn9y67ywc3bzw2l33k6400smhjn32-man-db-2.13.0/share/man/man1/man.1.gz
/usr/share/man/man7/man.7
/usr/share/man/man5/man.conf.5

In contrast, kitty does not set MANPATH, and manpath(1) will output a correct result.

# Running this in kitty

$ manpath
/Users/me/.nix-profile/share/man:/nix/var/nix/profiles/default/share/man:/System/Cryptexes/App/usr/share/man:/usr/share/man:/nix/store/4828bf36xkaldvd639q0vvmsapbi7jm3-kitty-0.37.0/share/man:/nix/store/w321n1ginns9sy16gqp3h6sfjdczjng9-imagemagick-7.1.1-40/share/man

$ man -aw man
/nix/store/a34dn9y67ywc3bzw2l33k6400smhjn32-man-db-2.13.0/share/man/man1/man.1.gz
/usr/share/man/man1/man.1
/usr/share/man/man7/man.7
/usr/share/man/man5/man.conf.5

man(1) knows how to derive manpath from PATH by default. So if MANPATH is correct, man(1) should open the manpage according to the order of PATH.

---

I am using ghostty 1.0.1 on macOS.

$ ghostty +version
Ghostty 1.0.1

Version
  - version: 1.0.1
  - channel: stable
Build Config
  - Zig version: 0.13.0
  - build mode : builtin.OptimizeMode.ReleaseFast
  - app runtime: apprt.Runtime.none
  - font engine: font.main.Backend.coretext
  - renderer   : renderer.Metal
  - libxev     : main.Backend.kqueue

[iawaknahc]

According to https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFBundles/BundleTypes/BundleTypes.html#//apple_ref/doc/uid/10000123i-CH101-SW20, it seems that the executable must be placed inside the directoryMacOS

According to man -s 5 manpath, it has the following behavior

By default, man-db examines the user's $PATH. For each path_element found there, it adds manpath_element to the search path.

If there is no MANPATH_MAP line in the configuration file for a given path_element, then it adds all of path_element/../man, path_element/man, path_element/../share/man, and path_element/share/man that exist as directories to the search path.

ghostty already puts /Applications/Ghostty.app/Contents/MacOS to PATH. If we put the man directory at /Applications/Ghostty.app/Contents/share/man (or other supported variations), then manpath should be able to add that to the search path. Then we do not even need to set MANPATH at all.