The error in the title is the result of a common TT2 "gotcha" . The solution is to give INCLUDE_PATH an arrayref, so a windows-style-directory isn't confused for a unix-style $PATH ( colon:s:e:p:a:r:a:t:e:d:list:of:directories )

diff -ruN old/Base.pm new/Base.pm
--- old/Base.pm 2011-05-04 09:06:57.000000000 -0700
+++ new/Base.pm 2012-05-12 02:55:35.171875000 -0700
@@ -95,11 +95,14 @@

     debug "Processing template $tmpl\n";
     my $out;
+    my %dconf = $me->tt_config; # Hook for sub-classes to add config
+    $dconf{INCLUDE_PATH} = [ $dconf{INCLUDE_PATH} ] if not ref $dconf
+{INCLUDE_PATH}
     my $tt = Template->new(
         #DEBUG    => $me->translator->debug,
+       #DEBUG => Template::Constants::DEBUG_ALL(),
         ABSOLUTE => 1,  # Set so we can use from the command line sen
+sibly
-        RELATIVE => 1,  # Maybe the cmd line code should set it! Secu
+rity!
-        $me->tt_config, # Hook for sub-classes to add config
+#        RELATIVE => 1,  # Maybe the cmd line code should set it! Sec
+urity!
+        %dconf,
         %args,          # Allow any TT opts to be passed in the produ
+cer_args
     ) || die "Failed to initialize Template object: ".Template->error
+;

@@ -107,7 +110,7 @@
         $me->tt_default_vars,
         $me->tt_vars,          # Sub-class hook for adding vars
     }, \$out )
-    or die "Error processing template '$tmpl': ".$tt->error;
+    or die "Error processing template '$tmpl': ".$tt->error ;

     return $out;
 }
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After that, the following generates output

sqlt -f SQLite -t -t DiaUml input > output

But naturally, foreign keys /UML relations are on the TODO list ;)