diff --git a/Makefile.local b/Makefile.local
--- a/Makefile.local
+++ b/Makefile.local
@@ -6,4 +6,11 @@
 	@echo Building the whole documentation from source code repositories
 	@echo available in ../ via tox. This can take a while.
 	@echo Please be patient.
-	tox -r -e sphinx-dev
+	tox -vv -r -e sphinx-dev
+
+pip-install-swh-dev:
+	python3 -m pip install pifpaf
+	sed 's/#.*$$//;/^$$/d' requirements-swh-dev.txt | \
+	while IFS= read -r package; do \
+	  python3 -m pip install $$package ; \
+	done
diff --git a/tox.ini b/tox.ini
--- a/tox.ini
+++ b/tox.ini
@@ -17,10 +17,10 @@
   {envpython} -m pifpaf run postgresql -- make -C docs {posargs:html}
 
 [testenv:sphinx-dev]
-deps =
-  django < 3
-  -rrequirements-swh-dev.txt
-  pifpaf
+allowlist_externals = make
+# workaround really long dependencies installation due to the
+# new pip resolver and its backtracking processes
+install_command = make pip-install-swh-dev {packages}
 setenv =
   SWHPKGDIR = {envsitepackagesdir}/swh
 commands =