docs: Disable parallel build for docs

It is not supported for docs

diff --git a/docs/Makefile.am b/docs/Makefile.am
index 78568e0c2b1527e5ed7a107c9776bd2c40b89ae7..0b234dd7647e3abbe13e39293db349e33fab8c80 100644 (file)
--- a/docs/Makefile.am
+++ b/docs/Makefile.am
@@ -63,6 +63,15 @@ endif # if !HAVE_MANPAGES
        .venv/bin/pip install -U pip setuptools setuptools-git
        .venv/bin/pip install -r requirements.txt
 
+.NOTPARALLEL: \
+       all-docs \
+       upload-docs \
+       html-docs \
+       $(MANPAGES_DIST) \
+       latex/PowerDNS-Authoritative.pdf \
+       PowerDNS-Authoritative.pdf \
+       html-docs.tar.bz2
+
 html-docs: common/** manpages/** .venv *.rst
        .venv/bin/python -msphinx -b html . html-docs