From 24dbf042a26036da17f5a996cd4232dfea699e06 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timoth=C3=A9e=20Ravier?= <tim@siosm.fr>
Date: Sun, 19 Jul 2015 11:00:04 +0200
Subject: [PATCH] docs: allow outside of Makefile variable assignment

This allow packagers to select the sphinx-build command version (python2
or python3) without changing the Makefile:

$ SPHINXBUILD=sphinx-build2 SPHINXOPTS=... make man
---
 docs/Makefile | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/docs/Makefile b/docs/Makefile
index 3b412210..c686ed80 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -1,8 +1,8 @@
 # Makefile for Sphinx documentation
-SPHINXOPTS    =
-SPHINXBUILD   = sphinx-build
-PAPER         =
-BUILDDIR      = _build
+SPHINXOPTS    ?=
+SPHINXBUILD   ?= sphinx-build
+PAPER         ?=
+BUILDDIR      ?= _build
 
 # Internal variables
 PAPEROPT_a4     = -D latex_paper_size=a4