doc: don't check for sphinx-build on `make clean`

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

diff --git a/doc/frr-sphinx.mk b/doc/frr-sphinx.mk
index 3d91e8f63dcb5acb06bc72a4f8912d584a9c96ab..df4056760d4dbbc87cea06a0abc6079870d4521d 100644 (file)
--- a/doc/frr-sphinx.mk
+++ b/doc/frr-sphinx.mk
@@ -11,11 +11,13 @@ PAPER         ?=
 BUILDDIR      = _build
 
 # User-friendly check for sphinx-build
-ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
-SPHINXBUILD = sphinx-1.0-build
-endif
-ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
-$(error "The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD make variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/")
+ifneq ($(MAKECMDGOALS), clean)
+    ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
+        SPHINXBUILD = sphinx-1.0-build
+    endif
+    ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
+        $(error "The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD make variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/")
+    endif
 endif
 
 # Internal variables.