docs: make varaibles environment-aware

There are all overwriting the environment, even the comment states otherwise. Fixes it.
2020-09-23 20:29:47 +02:00 · 2020-09-23 20:29:47 +02:00 · 84a7818121
parent b6922508b9
commit 84a7818121
1 changed files with 4 additions and 4 deletions
--- a/docs/src/Makefile
+++ b/docs/src/Makefile
@ -2,10 +2,10 @@
 #

 # You can set these variables from the command line.
-SPHINXOPTS    =
-SPHINXBUILD   = sphinx-build
-PAPER         =
-BUILDDIR      = ../dist
+SPHINXOPTS   ?=
+SPHINXBUILD  ?= sphinx-build
+PAPER        ?=
+BUILDDIR     ?= ../dist
 # for cache, etc.
 _BUILDDIR     = _build