diff --git a/bin/hc b/bin/hc
index 5572362..69756f8 100644
--- a/bin/hc
+++ b/bin/hc
@@ -4,6 +4,7 @@
 
 import sys
 import os
+import errno
 import hypercane.cli.sample, hypercane.cli.identify, \
     hypercane.cli.order, hypercane.cli.cluster, \
     hypercane.cli.score, hypercane.cli.synthesize, \
@@ -37,6 +38,8 @@ This is the list of supported actions:
     print("""
 For each of these actions, you can view additional help by typing --help after the action name, for example:
     hc sample --help
+
+Please read Hypercane's documentation at https://hypercane.readthedocs.io/en/latest/
 """)
 
 if __name__ == '__main__':
@@ -56,7 +59,14 @@ if __name__ == '__main__':
 
             args = sys.argv[2:]
 
-            scriptname = os.path.abspath(supported_actions[action])
+            try:
+                scriptname = os.path.abspath(supported_actions[action])
+            except KeyError:
+                print("hc: error: unknown action {}\n".format(action))
+                print_overall_usage()
+                sys.exit(errno.EINVAL)
+
+            print("scriptname: {}".format(scriptname))
 
             arglist = ""
             for arg in args:
@@ -70,3 +80,4 @@ if __name__ == '__main__':
     else:
         print("hc: error: no action supplied\n")
         print_overall_usage()
+        sys.exit(errno.EINVAL)
diff --git a/docs/source/conf.py b/docs/source/conf.py
index 3b055a2..84f1698 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -26,7 +26,7 @@
 # The short X.Y version
 version = u''
 # The full version, including alpha/beta/rc tags
-release = u'0.2021.07.20.233812'
+release = u'0.2021.09.08.205939'
 
 # -- General configuration ---------------------------------------------------
 
diff --git a/hypercane-gui/install-gui.sh b/hypercane-gui/install-gui.sh
index 1fb68c6..925a3d2 100755
--- a/hypercane-gui/install-gui.sh
+++ b/hypercane-gui/install-gui.sh
@@ -9,6 +9,8 @@ JUST_TEMPLATES=1
 OVERRIDE_VIRTUALENV_CHECK=0
 WOOEY_DIR=${SCRIPT_DIR}/../hypercane_with_wooey
 
+echo "using script directory '${SCRIPT_DIR}'"
+
 while test $# -gt 0; do
 
     case "$1" in
diff --git a/hypercane-gui/scripts/filter exclude.py b/hypercane-gui/scripts/filter exclude.py
index a8977f1..9c77a00 100644
--- a/hypercane-gui/scripts/filter exclude.py	
+++ b/hypercane-gui/scripts/filter exclude.py	
@@ -6,6 +6,8 @@
     formatter_class=RawTextHelpFormatter
 )
 
-args = parser.parse_args()
+if __name__ == '__main__':
 
-print("Not implemented yet.")
+    args = parser.parse_args()
+
+    print("Not implemented yet.")
diff --git a/hypercane-gui/scripts/filter include-only.py b/hypercane-gui/scripts/filter include-only.py
index 2c9cb4c..8442053 100644
--- a/hypercane-gui/scripts/filter include-only.py	
+++ b/hypercane-gui/scripts/filter include-only.py	
@@ -6,6 +6,8 @@
     formatter_class=RawTextHelpFormatter
 )
 
-args = parser.parse_args()
+if __name__ == '__main__':
 
-print("Not implemented yet.")
+    args = parser.parse_args()
+
+    print("Not implemented yet.")
diff --git a/hypercane/args/synthesize.py b/hypercane/args/synthesize.py
index aa31213..8fd7253 100644
--- a/hypercane/args/synthesize.py
+++ b/hypercane/args/synthesize.py
@@ -55,7 +55,6 @@
 
 raintalestory_parser.add_argument('--termdata', dest='termdata_filename',
     help='A file containing term data, as produced by hc report terms',
-    output_extension='.tsv',
     required=False, default=None
 )
 
diff --git a/hypercane/version.py b/hypercane/version.py
index 07e393a..0bf1279 100644
--- a/hypercane/version.py
+++ b/hypercane/version.py
@@ -1,3 +1,3 @@
 __appname__ = "hypercane"
-__appversion__ = '0.2021.07.20.233812'
+__appversion__ = '0.2021.09.08.205939'
 __useragent__ = "{}/{}".format(__appname__, __appversion__)