[docs] Point to upstream Sphinx install instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292752 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/docs/CMake.rst b/docs/CMake.rst
index 05885779efdfaccdfab1b199dd959ddbcaaa1fec..0a32d3957a53cd59f2efaff7266e197b6a759150 100644 (file)
--- a/docs/CMake.rst
+++ b/docs/CMake.rst
@@ -469,6 +469,8 @@ LLVM-specific variables
 
 **SPHINX_EXECUTABLE**:STRING
   The path to the ``sphinx-build`` executable detected by CMake.
+  For installation instructions, see
+  http://www.sphinx-doc.org/en/latest/install.html
 
 **SPHINX_OUTPUT_HTML**:BOOL
   If enabled (and ``LLVM_ENABLE_SPHINX`` is enabled) then the targets for