lowercase m in macOS

(cherry picked from commit 2cc7c4d62c7266171e9958ea3099efc61b061a10)

diff --git a/README.md b/README.md
index 139e615b4ad4e5f43be2f710a521e8b5172773a4..5b7dc1d0104ab26aa5cf9064cb864f7447c94daa 100644 (file)
--- a/README.md
+++ b/README.md
@@ -14,6 +14,7 @@
 1. [Contributing to BIND](#contrib)
 1. [BIND 9.12 features](#features)
 1. [Building BIND](#build)
+1. [macOS](#macos)
 1. [Compile-time options](#opts)
 1. [Automated testing](#testing)
 1. [Documentation](#doc)
@@ -171,6 +172,14 @@ affect compilation:
 |`BUILD_LDFLAGS`||
 |`BUILD_LIBS`||
 
+#### <a name="macos"> macOS
+
+Building on macOS assumes that the "Command Tools for Xcode" is installed.
+This can be downloaded from https://developer.apple.com/download/more/
+or if you have Xcode already installed you can run "xcode-select --install".
+This will add /usr/include to the system and install the compiler and other
+tools so that they can be easily found.
+
 #### <a name="opts"/> Compile-time options
 
 To see a full list of configuration options, run `configure --help`.