diff --git a/pyproject.toml b/pyproject.toml
index 25402296..fe68909f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -105,6 +105,7 @@ all = [
     "modeci-mdf[all_except_psyneulink]",
     "modeci-mdf[psyneulink]",
     "modeci-mdf[neuroml_simulators]",
+    "modeci-mdf[test]",
 ]
 
 # Development dependency groups (PEP 735)
diff --git a/test_all.sh b/test_all.sh
index 41816de5..2cdd717a 100755
--- a/test_all.sh
+++ b/test_all.sh
@@ -1,7 +1,24 @@
 #!/bin/bash
 set -ex
 
-pip install .[all] --group "dev"
+## This is overkill, but it seems to lead to less space being used on install, which was
+## causing issues on GHA CI.
+df -h
+
+pip install . --cache-dir=/home/runner/tmp --prefer-binary
+df -h
+pip cache info
+pip cache purge
+df -h
+
+pip install .[optional] --cache-dir=/home/runner/tmp --prefer-binary
+df -h
+pip cache purge
+df -h
+
+pip install .[all] --cache-dir=/home/runner/tmp --prefer-binary
+df -h
+
 
 # Note this:
 #    1) runs examples to regenerate yaml/json...