Because files on OS X are assigned the group of the directory in which they are created, using /tmp during the installation process would result in some installed files having the group "wheel" even though "admin" was intended. Thanks to Xu Cheng for suggesting a simpler location for the fix. Closes Homebrew/homebrew#45869 Closes Homebrew/homebrew#48732. Signed-off-by: Xu Cheng <xucheng@me.com>