tooling: Fix installation of documentation dependencies

It's been simplified into a requirements.txt file, which can also
be used by Github Actions. We can't automatically install Sphinx
with pipx though, but a user who wants it should be able to figure
it out easily enough.

Author: cassava

Makefile.setup

@@ -41,6 +41,7 @@ help::
 	echo "  setup                 to perform Git repository setup"
 	echo "  install-system-deps   to install build (and development) system requirements"
 	echo "  install-python-deps   to install Python runtime requirements with ${PIP}"
+	echo "  install-sphinx-deps   to install Sphinx runtime requirements with ${PIP}"
 	echo "  install-python-tools  to install Python development tools with ${PIPX}"
 	echo
 
@@ -66,6 +67,7 @@ install-ubuntu-deps::
 		curl \
 		file \
 		git \
+		graphviz \
 		jq \
 		patchelf \
 		psmisc \
@@ -99,6 +101,7 @@ install-archlinux-deps::
 		curl \
 		doxygen \
 		git \
+		graphviz \
 		jq \
 		patchelf \
 		psmisc \
@@ -117,19 +120,20 @@ install-archlinux-deps::
 endif
 
 # Python ----------------------------------------------------------------------
-ifdef PIP
-install-deps:: install-python-deps install-python-tools
-endif
-
 install-python-deps::
 	command -v ${PIP} >/dev/null 2>&1
 	${PIP} install ${PIP_INSTALL_ARGS} \
 		click \
 		conan \
 		libtmux \
 		toml \
+		pipx \
 		;
 
+install-sphinx-deps:
+	command -v ${PIP} >/dev/null 2>&1
+	${PIP} install ${PIP_INSTALL_ARGS} -r docs/requirements.txt
+
 install-python-tools::
 	command -v ${PIPX} >/dev/null 2>&1
 	for pkg in \

docs/Makefile

@@ -24,24 +24,8 @@ help:
 	echo "Available serving targets:"
 	echo "  serve          to serve the documentation on 0.0.0.0:8000"
 	echo "  livehtml       to autobuild and serve the documentation on localhost:8000"
-	echo
-	echo "Available setup targets:"
-	echo "  install-sphinx-deps    to install dependencies for sphinx"
-
-.PHONY: install-sphinx-deps serve livehtml
-
-SPHINXDEPS := \
-	sphinx_rtd_theme \
-	sphinxcontrib-runcmd \
-	sphinxcontrib-plantuml \
-	sphinxcontrib.asciinema \
-	jsx-lexer
-install-sphinx-deps:
-	pipx install sphinx
-	pipx inject sphinx ${SPHINXDEPS}
-	pipx install sphinx-autobuild
-	pipx inject sphinx-autobuild ${SPHINXDEPS}
 
+.PHONY: serve livehtml
 serve:
 	cd ${BUILDDIR}/html && python3 -m http.server
 

docs/requirements.txt

@@ -0,0 +1,8 @@
+sphinx
+sphinx-autobuild
+sphinx_rtd_theme
+sphinxcontrib-runcmd
+sphinxcontrib-plantuml
+sphinxcontrib.asciinema
+jsx-lexer
+pygments>=2.7