bpo-36838: Suggest 'make venv' when missing Doc/ tools. (GH-13173)

diff --git a/Doc/Makefile b/Doc/Makefile
index 53877e61329089f878c52938fe10e1bf4cb7ffa7..cf1bb88b0b8ea410e7f2568e4a590cf838a5fe7a 100644 (file)
--- a/Doc/Makefile
+++ b/Doc/Makefile
@@ -48,11 +48,19 @@ build:
        @if [ -f  ../Misc/NEWS ] ; then \
                echo "Using existing Misc/NEWS file"; \
                cp ../Misc/NEWS build/NEWS; \
-       elif [ -d ../Misc/NEWS.d ]; then \
-               echo "Building NEWS from Misc/NEWS.d with blurb"; \
-               $(BLURB) merge -f build/NEWS; \
+       elif $(BLURB) help >/dev/null 2>&1 && $(SPHINXBUILD) --version >/dev/null 2>&1; then \
+               if [ -d ../Misc/NEWS.d ]; then \
+                       echo "Building NEWS from Misc/NEWS.d with blurb"; \
+                       $(BLURB) merge -f build/NEWS; \
+               else \
+                       echo "Neither Misc/NEWS.d nor Misc/NEWS found; cannot build docs"; \
+                       exit 1; \
+               fi \
        else \
-               echo "Neither Misc/NEWS.d nor Misc/NEWS found; cannot build docs"; \
+               echo ""; \
+               echo "Missing the required blurb or sphinx-build tools."; \
+               echo "Please run 'make venv' to install local copies."; \
+               echo ""; \
                exit 1; \
        fi
        $(SPHINXBUILD) $(ALLSPHINXOPTS)