fix(brew): add sbin to PATH (#13780)

plugins/brew/README.md

@@ -17,6 +17,12 @@ If `brew` is not found in the PATH, this plugin will attempt to find it in commo
 In case you installed `brew` in a non-common location, you can still set `BREW_LOCATION` variable pointing to
 the `brew` binary before sourcing `oh-my-zsh.sh` and it'll set up the environment.
 
+### sbin directory
+
+This plugin also adds `$HOMEBREW_PREFIX/sbin` to the PATH if the directory exists and isn't already present.
+Some Homebrew formulae (e.g. `mtr`) install executables to `sbin`, which `brew doctor` checks for. This
+ensures the `bdr` alias runs without warnings.
+
 ## Aliases
 
 | Alias    | Command                                 | Description                                                           |

plugins/brew/brew.plugin.zsh

@@ -30,6 +30,16 @@ if [[ -z "$HOMEBREW_PREFIX" ]]; then
   export HOMEBREW_PREFIX="$(brew --prefix)"
 fi
 
+# Add Homebrew sbin to PATH if it exists and is not already in PATH.
+# Homebrew's shellenv only adds bin directories, not sbin. Some formulae
+# (e.g. mtr) install executables to sbin, and brew doctor warns if it's
+# missing from PATH.
+if [[ -d "$HOMEBREW_PREFIX/sbin" ]]; then
+  if [[ ! "$PATH" == *"$HOMEBREW_PREFIX/sbin"* ]]; then
+    export PATH="$HOMEBREW_PREFIX/sbin:$PATH"
+  fi
+fi
+
 if [[ -d "$HOMEBREW_PREFIX/share/zsh/site-functions" ]]; then
   fpath+=("$HOMEBREW_PREFIX/share/zsh/site-functions")
 fi