diff -r e8c39b3f2a24 doc/ns3_html_theme/get_version.sh
--- a/doc/ns3_html_theme/get_version.sh	Fri Oct 27 18:47:53 2017 -0700
+++ b/doc/ns3_html_theme/get_version.sh	Thu Nov 02 19:37:01 2017 -0700
@@ -138,28 +138,33 @@
 
 # Distance from last tag
 # Zero distance means we're at the tag
-distance=`hg log -r tip --template '{latesttagdistance}'`
+if [ -x "$(command -v hg)" ]; then
+    distance=`hg log -r tip --template '{latesttagdistance}'`
 
-if [ $distance -eq 1 ]; then
-    version=`hg log -r tip --template '{latesttag}'`
-    say "at tag $version"
+    if [ $distance -eq 1 ]; then
+        version=`hg log -r tip --template '{latesttag}'`
+        say "at tag $version"
 
-elif [ $tag -eq 1 ]; then
-    distance=1
-    # version previously set
-    vers_href=
+    elif [ $tag -eq 1 ]; then
+        distance=1
+        # version previously set
+        vers_href=
 
+    else
+        version=`hg log -r tip --template '{node|short}'`
+        # Check for uncommitted changes
+        hg summary | grep 'commit:' | grep -q '(clean)'
+        if [ ! $? ] ; then
+	    say "beyond latest tag, last commit: $version, dirty"
+	    dirty="(+)"
+        else
+	    say "beyond latest tag, last commit: $version, clean"
+	    dirty=
+        fi
+    fi
 else
-    version=`hg log -r tip --template '{node|short}'`
-    # Check for uncommitted changes
-    hg summary | grep 'commit:' | grep -q '(clean)'
-    if [ ! $? ] ; then
-	say "beyond latest tag, last commit: $version, dirty"
-	dirty="(+)"
-    else
-	say "beyond latest tag, last commit: $version, clean"
-	dirty=
-    fi
+    version="version-not-found"
+    say "hg not found; version will not be printed"
 fi
 
 if [ $PUBLIC -eq 1 ]; then
@@ -191,7 +196,11 @@
     echo "// ns3_version.js:  automatically generated"       >  $outf
     echo "//  private urls"                                  >> $outf
     echo "var ns3_host = \"file://$PWD/\";"                  >  $outf
-    echo "var ns3_version = \"$repo @ $version$dirty\";"     >> $outf
+    if [ $version == "version-not-found" ]; then
+        echo "var ns3_version = \"$repo\";"                  >> $outf
+    else
+        echo "var ns3_version = \"$repo @ $version$dirty\";" >> $outf
+    fi
     echo "var ns3_release = \"doc/\";"                       >> $outf
     echo "var ns3_local = \"build/\";"                       >> $outf
     echo "var ns3_doxy  = \"html/\";"                        >> $outf