diff --git a/VERSION b/VERSION
index 464347a..e95267c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.195
+1.5.196
diff --git a/base/netcmp.c b/base/netcmp.c
index e4f5d41..5641fea 100644
--- a/base/netcmp.c
+++ b/base/netcmp.c
@@ -4121,6 +4121,7 @@ void series_sort(struct objlist *ob1, struct nlist *tp1, int idx1, int run)
    sval = 1;
    cval = slop = 0.0;
    for (i = 0; i < run; i++) {
+      sl = NULL;
       merge_type = MERGE_NONE;
       for (p = 0;; p++) {
 	 vl = &(obp->instance.props[p]);
@@ -4149,13 +4150,13 @@ void series_sort(struct objlist *ob1, struct nlist *tp1, int idx1, int run)
 	 proplist[i].value = cval * (double)sval;
          proplist[i].slop = slop;
          proplist[i].avalue = 0;
-	 sl->value.ival = 1;
+	 if (sl) sl->value.ival = 1;
       }
       else if (merge_type == MERGE_S_PAR) {
 	 proplist[i].value = cval / (double)sval;
          proplist[i].slop = slop;
          proplist[i].avalue = 0;
-	 sl->value.ival = 1;
+	 if (sl) sl->value.ival = 1;
       }
       else {
 	 /* Components which declare no series addition method stay unsorted */
diff --git a/python/lvs_manager.py b/python/lvs_manager.py
new file mode 100644
index 0000000..cd8559a
--- /dev/null
+++ b/python/lvs_manager.py
@@ -0,0 +1,891 @@
+#!/bin/env python3
+#
+#--------------------------------------------------------
+# LVS Manager GUI.
+#
+# This is a Python tkinter script that handles the
+# process of running LVS and interpreting results.
+#
+#--------------------------------------------------------
+# Written by Tim Edwards
+# efabless, inc.
+# Version 1.  November 30, 2016
+# Version 2.  March 6, 2017.  Reads JSON format output
+# Version 3.  April 25, 2018. Handles layout vs. verilog
+#--------------------------------------------------------
+
+import io
+import os
+import re
+import sys
+import json
+import shutil
+import signal
+import socket
+import select
+import datetime
+import contextlib
+import subprocess
+
+import tkinter
+from tkinter import ttk
+from tkinter import filedialog
+
+import tksimpledialog
+import tooltip
+from consoletext import ConsoleText
+from helpwindow import HelpWindow
+from treeviewsplit import TreeViewSplit
+
+# User preferences file (if it exists)
+prefsfile = '~/.profile/prefs.json'
+
+netgen_script_dir = '/usr/local/lib/netgen/python'
+
+#------------------------------------------------------
+# Simple dialog for confirming quit
+#------------------------------------------------------
+
+class ConfirmDialog(tksimpledialog.Dialog):
+    def body(self, master, warning, seed):
+        if warning:
+            ttk.Label(master, text=warning, wraplength=500).grid(row = 0, columnspan = 2, sticky = 'wns')
+        return self
+
+    def apply(self):
+        return 'okay'
+
+#------------------------------------------------------
+# Main class for this application
+#------------------------------------------------------
+
+class LVSManager(ttk.Frame):
+    """LVS Manager GUI."""
+
+    def __init__(self, parent, *args, **kwargs):
+        ttk.Frame.__init__(self, parent, *args, **kwargs)
+        self.root = parent
+        self.init_gui()
+        parent.protocol("WM_DELETE_WINDOW", self.on_quit)
+
+    def on_quit(self):
+        """Exits program."""
+        if self.msock:
+            self.msock.close()
+        quit()
+
+    def init_gui(self):
+        """Builds GUI."""
+        global prefsfile
+
+        message = []
+        fontsize = 11
+
+        # Read user preferences file, get default font size from it.
+        prefspath = os.path.expanduser(prefsfile)
+        if os.path.exists(prefspath):
+            with open(prefspath, 'r') as f:
+                self.prefs = json.load(f)
+            if 'fontsize' in self.prefs:
+                fontsize = self.prefs['fontsize']
+        else:
+            self.prefs = {}
+
+        s = ttk.Style()
+
+        available_themes = s.theme_names()
+        s.theme_use(available_themes[0])
+
+        s.configure('bg.TFrame', background='gray40')
+        s.configure('italic.TLabel', font=('Helvetica', fontsize, 'italic'))
+        s.configure('title.TLabel', font=('Helvetica', fontsize, 'bold italic'),
+                        foreground = 'brown', anchor = 'center')
+        s.configure('normal.TLabel', font=('Helvetica', fontsize))
+        s.configure('red.TLabel', font=('Helvetica', fontsize), foreground = 'red')
+        s.configure('green.TLabel', font=('Helvetica', fontsize), foreground = 'green3')
+        s.configure('blue.TLabel', font=('Helvetica', fontsize), foreground = 'blue')
+        s.configure('normal.TButton', font=('Helvetica', fontsize),
+                        border = 3, relief = 'raised')
+        s.configure('red.TButton', font=('Helvetica', fontsize), foreground = 'red',
+                        border = 3, relief = 'raised')
+        s.configure('green.TButton', font=('Helvetica', fontsize), foreground = 'green3',
+                        border = 3, relief = 'raised')
+        s.configure('blue.TButton', font=('Helvetica', fontsize), foreground = 'blue',
+                        border = 3, relief = 'raised')
+        s.configure('redtitle.TButton', font=('Helvetica', fontsize, 'bold italic'),
+                        foreground = 'red', border = 3, relief = 'raised')
+        s.configure('bluetitle.TButton', font=('Helvetica', fontsize, 'bold italic'),
+                        foreground = 'blue', border = 3, relief = 'raised')
+
+        # These values to be overridden from arguments
+        self.rootpath = None
+        self.project = None
+        self.logfile = None
+        self.msock = None
+        self.help = None
+
+        # Create the help window
+        if os.path.exists(netgen_script_dir + '/netgen_help.txt'):
+            self.help = HelpWindow(self, fontsize = fontsize)
+            with io.StringIO() as buf, contextlib.redirect_stdout(buf):
+                self.help.add_pages_from_file('lvs_help.txt')
+                message = buf.getvalue()
+
+            # Set the help display to the first page
+            self.help.page(0)
+
+        # Variables used by option menus and other stuff
+        self.project = "(no selection)"
+        self.layout = "(default)"
+        self.schematic = "(default)"
+        self.tech = "(none)"
+        self.lvs_setup = ''
+        self.lvsdata = {}
+
+        # Root window title
+        self.root.title('LVS Manager')
+        self.root.option_add('*tearOff', 'FALSE')
+        self.pack(side = 'top', fill = 'both', expand = 'true')
+
+        pane = tkinter.PanedWindow(self, orient = 'vertical', sashrelief='groove', sashwidth=6)
+        pane.pack(side = 'top', fill = 'both', expand = 'true')
+        self.toppane = ttk.Frame(pane)
+        self.botpane = ttk.Frame(pane)
+
+        # Get username
+        if 'username' in self.prefs:
+            username = self.prefs['username']
+        else:
+            username = os.environ['USER']
+
+        # Label with the user
+        self.toppane.title_frame = ttk.Frame(self.toppane)
+        self.toppane.title_frame.pack(side = 'top', fill = 'x')
+
+        self.toppane.title_frame.title = ttk.Label(self.toppane.title_frame, text='User:', style = 'red.TLabel')
+        self.toppane.title_frame.user = ttk.Label(self.toppane.title_frame, text=username, style = 'blue.TLabel')
+
+        self.toppane.title_frame.title.grid(column=0, row=0, ipadx = 5)
+        self.toppane.title_frame.user.grid(column=1, row=0, ipadx = 5)
+
+        self.toppane.title2_frame = ttk.Frame(self.toppane)
+        self.toppane.title2_frame.pack(side = 'top', fill = 'x')
+        self.toppane.title2_frame.project_label = ttk.Label(self.toppane.title2_frame, text="Project:",
+                style = 'title.TLabel')
+        self.toppane.title2_frame.project_label.grid(column=0, row=0, ipadx = 5)
+
+        # New project select button
+        self.toppane.title2_frame.project_select = ttk.Button(self.toppane.title2_frame,
+                text=self.project, style='normal.TButton', command=self.choose_project)
+        self.toppane.title2_frame.project_select.grid(column=1, row=0, ipadx = 5)
+
+        tooltip.ToolTip(self.toppane.title2_frame.project_select,
+                        text = "Select new project")
+
+        # Show path to project
+        self.toppane.title2_frame.path_label = ttk.Label(self.toppane.title2_frame, text=self.project,
+                style = 'normal.TLabel')
+        self.toppane.title2_frame.path_label.grid(column=2, row=0, ipadx = 5, padx = 10)
+
+        # Show top-level layout cellname with select button.  Initial cell name is the top-level cell.
+        self.toppane.title2_frame.tech_label = ttk.Label(self.toppane.title2_frame, text="Technology setup:",
+                style = 'title.TLabel')
+
+        self.toppane.title2_frame.tech_label.grid(column=3, row=0, ipadx = 5)
+        self.toppane.title2_frame.tech_select = ttk.Button(self.toppane.title2_frame,
+                text=self.tech, style='normal.TButton', command=self.choose_tech)
+        self.toppane.title2_frame.tech_select.grid(column=4, row=0, ipadx = 3, padx = 3)
+
+        self.toppane.title2_frame.layout_label = ttk.Label(self.toppane.title2_frame, text="Layout:",
+                style = 'title.TLabel')
+        self.toppane.title2_frame.layout_label.grid(column=0, row=1, ipadx = 5)
+        self.toppane.title2_frame.layout_select = ttk.Button(self.toppane.title2_frame,
+                text=self.layout, style='normal.TButton', command=self.choose_layout)
+        self.toppane.title2_frame.layout_select.grid(column=1, row=1, ipadx = 3, padx = 3)
+
+        # Show top-level schematic cellname with select button.  Initial cell name is the top-level cell.
+        self.toppane.title2_frame.schem_label = ttk.Label(self.toppane.title2_frame, text="Schematic:",
+                style = 'title.TLabel')
+        self.toppane.title2_frame.schem_label.grid(column=3, row=1, ipadx = 5)
+        self.toppane.title2_frame.schem_select = ttk.Button(self.toppane.title2_frame,
+                text=self.schematic, style='normal.TButton', command=self.choose_netlist)
+        self.toppane.title2_frame.schem_select.grid(column=4, row=1, ipadx = 3, padx = 3)
+
+        tooltip.ToolTip(self.toppane.title2_frame.project_select,
+                        text = "Select new project")
+        tooltip.ToolTip(self.toppane.title2_frame.layout_select,
+                        text = "Select a layout subcirucit to compare")
+        tooltip.ToolTip(self.toppane.title2_frame.schem_select,
+                        text = "Select a schematic subcirucit to compare")
+
+        #---------------------------------------------
+        ttk.Separator(self.toppane, orient='horizontal').pack(side = 'top', fill = 'x')
+        #---------------------------------------------
+
+        # Create listbox of Circuit1 vs. Circuit2 results
+        height = 10
+        self.toppane.lvsreport = TreeViewSplit(self.toppane, fontsize = fontsize)
+        self.toppane.lvsreport.populate("Layout:", [], "Schematic:", [],
+			[["Run", True, self.run_lvs],
+			# ["Find", True, self.findrecord]
+			], height = height)
+        self.toppane.lvsreport.set_title("Line")
+        self.toppane.lvsreport.pack(side = 'top', fill = 'both', expand = 'true')
+
+        tooltip.ToolTip(self.toppane.lvsreport.get_button(0), text="Run LVS")
+
+        #---------------------------------------------
+        # ttk.Separator(self, orient='horizontal').grid(column=0, row=3, sticky='ew')
+        #---------------------------------------------
+
+        # Add a text window below the project name to capture output.  Redirect
+        # print statements to it.
+
+        self.botpane.console = ttk.Frame(self.botpane)
+        self.botpane.console.pack(side = 'top', fill = 'both', expand = 'true')
+
+        self.text_box = ConsoleText(self.botpane.console, wrap='word', height = 4)
+        self.text_box.pack(side='left', fill='both', expand='true')
+        console_scrollbar = ttk.Scrollbar(self.botpane.console)
+        console_scrollbar.pack(side='right', fill='y')
+        # attach console to scrollbar
+        self.text_box.config(yscrollcommand = console_scrollbar.set)
+        console_scrollbar.config(command = self.text_box.yview)
+
+        # Add button bar at the bottom of the window
+        self.botpane.bbar = ttk.Frame(self.botpane)
+        self.botpane.bbar.pack(side = 'top', fill = 'x')
+
+        # Define the "quit" button and action
+        self.botpane.bbar.quit_button = ttk.Button(self.botpane.bbar, text='Quit', command=self.on_quit,
+                style = 'normal.TButton')
+        self.botpane.bbar.quit_button.grid(column=0, row=0, padx = 5)
+
+        # Define help button
+        if self.help:
+            self.botpane.bbar.help_button = ttk.Button(self.botpane.bbar, text='Help',
+		command=self.help.open, style = 'normal.TButton')
+            self.botpane.bbar.help_button.grid(column = 2, row = 0, padx = 5)
+            tooltip.ToolTip(self.botpane.bbar.help_button, text = "Show help window")
+
+        # Add the panes once the internal geometry is known.
+        pane.add(self.toppane)
+        pane.add(self.botpane)
+        pane.paneconfig(self.toppane, stretch='first')
+
+        # Redirect stdout and stderr to the console as the last thing to do. . .
+        # Otherwise errors in the GUI get sucked into the void.
+
+        self.stdout = sys.stdout
+        self.stderr = sys.stderr
+        sys.stdout = ConsoleText.StdoutRedirector(self.text_box)
+        sys.stderr = ConsoleText.StderrRedirector(self.text_box)
+
+        if message:
+            print(message)
+
+    def logprint(self, message, doflush=False):
+        if self.logfile:
+            self.logfile.buffer.write(message.encode('utf-8'))
+            self.logfile.buffer.write('\n'.encode('utf-8'))
+            if doflush:
+                self.logfile.flush()
+
+    def printout(self, output):
+        # Generate output
+        if not output:
+            return
+
+        outlines = output.splitlines()
+        for line in outlines:
+            try:
+                print(line)
+            except TypeError:
+                line = line.decode('utf-8')
+                pritn(line)
+
+    def printwarn(self, output):
+        # Check output for warning or error
+        if not output:
+            return 0
+
+        warnrex = re.compile('.*warning', re.IGNORECASE)
+        errrex = re.compile('.*error', re.IGNORECASE)
+
+        errors = 0
+        outlines = output.splitlines()
+        for line in outlines:
+            try:
+                wmatch = warnrex.match(line)
+            except TypeError:
+                line = line.decode('utf-8')
+                wmatch = warnrex.match(line)
+            ematch = errrex.match(line)
+            if ematch:
+                errors += 1
+            if ematch or wmatch:
+                print(line)
+        return errors
+
+    def choose_tech(self):
+        try:
+            project_path = self.rootpath
+            initdirname = self.rootpath + '/tech',
+        except:
+            print('Must choose a project first.')
+            return
+        techname = filedialog.askopenfilename(multiple=False,
+			initialdir = initdirname,
+			filetypes = (("Tcl script", "*.tcl"),("All Files","*.*")),
+			title = "Choose a netgen technology setup script.")
+        if techname != '':
+            print("Selected technology setup script " + techname)
+            techbase = os.path.split(techname)[1]
+            self.tech = os.path.splitext(techbase)[0]
+            self.lvs_setup = techname
+            self.toppane.title2_frame.tech_select.config(text = self.tech)
+
+    def choose_layout(self):
+        try:
+            project_path = self.rootpath
+            initdirname = self.rootpath + '/layout',
+        except:
+            print('Must choose a project first.')
+            return
+        cellname = filedialog.askopenfilename(multiple=False,
+			initialdir = initdirname,
+			filetypes = (("Magic layout", "*.mag"),("All Files","*.*")),
+			title = "Choose a layout cell to compare.")
+        if cellname != '':
+            print("Selected compare cell " + cellname)
+            self.layout = cellname
+            cellbase = os.path.split(cellname)[1]
+            layoutname = os.path.splitext(cellbase)[0]
+            self.toppane.title2_frame.layout_select.config(text = layoutname)
+            fileext = os.path.splitext(cellbase)[1]
+            if fileext == '.mag':
+                self.toppane.title2_frame.layout_label.config(text = 'Layout:')
+            else:
+                self.toppane.title2_frame.layout_label.config(text = 'Layout netlist:')
+
+    def choose_netlist(self):
+        try:
+            project_path = self.rootpath
+            initdirname = self.rootpath + '/netlist/' + self.project + '.spice'
+        except:
+            print('Must choose a project first.')
+            return
+        cellname = filedialog.askopenfilename(multiple=False,
+			initialdir = initdirname,
+			filetypes = (("Spice netlist", "*.spice"),("Verilog netlist", "*.v"),("All Files","*.*")),
+			title = "Choose a netlist to compare.")
+        if cellname != '':
+            print("Selected compare cell " + cellname)
+            self.schematic = cellname
+            cellbase = os.path.split(cellname)[1]
+            schematic_name = os.path.splitext(cellbase)[0]
+            self.toppane.title2_frame.schem_select.config(text = schematic_name)
+            fileext = os.path.splitext(cellbase)[1]
+            if fileext == '.v':
+                self.toppane.title2_frame.schem_label.config(text = 'Verilog netlist:')
+            elif fileext == '.sp' or fileext == '.spice' or fileext == '.spi' or fileext == '.spc' or fileext == '.ckt':
+                self.toppane.title2_frame.schem_label.config(text = 'SPICE netlist:')
+            elif fileext == '.cdl':
+                self.toppane.title2_frame.schem_label.config(text = 'CDL netlist:')
+            else:
+                self.toppane.title2_frame.schem_label.config(text = 'Unknown netlist:')
+
+    def choose_project(self):
+        project = filedialog.askdirectory(initialdir = os.getcwd(),
+			title = "Find a project.")
+        if project != '':
+            print("Selected project " + str(project))
+            result = self.set_project(project)
+
+    def set_project(self, rootpath, project_name=None):
+
+        # Check if rootpath is valid.  For LVS, there should be subdirectories
+        # "layout/" and "netlist/" or "verilog/".
+
+        haslay = os.path.isdir(rootpath + '/layout')
+        hasvlog = os.path.isdir(rootpath + '/verilog')
+        hasnet = os.path.isdir(rootpath + '/netlist')
+        if not haslay or not (hasvlog or hasnet):
+            if not haslay:
+                print("Project path has no layout (/layout) subdirectory.")
+            if not (hasvlog or hasnet):
+                print("Project path has no verilog (/verilog), or netlist (/netlist) subdirectory.")
+            # Continue anyway;  assume that netlists will be selected manually
+
+        if self.logfile:
+            self.logfile.close()
+            self.logfile = None
+
+        if not project_name:
+            project = os.path.split(rootpath)[1]
+        else:
+            project = project_name
+
+        if self.project != project:
+
+            self.rootpath = rootpath
+            self.project = project
+
+            # Clear out old project data
+            self.toppane.lvsreport.repopulate([], [])
+
+            # Close any open logfile.
+            if self.logfile:
+                self.logfile.close()
+                self.logfile = None
+
+            # Put new log file called 'lvs.log' in the mag/ subdirectory
+            if os.path.exists(rootpath + '/layout'):
+                self.logfile = open(rootpath + '/layout/lvs.log', 'w')
+            else:
+                self.logfile = open(rootpath + '/lvs.log', 'w')
+            # Print some initial information to the logfile.
+            self.logprint('Starting new log file ' + datetime.datetime.now().strftime('%c'),
+				doflush=True)
+
+            # Update project button
+            self.toppane.title2_frame.project_select.config(text = self.project)
+            self.toppane.title2_frame.path_label.config(text = self.rootpath)
+            # Cell name is the same as project name initially
+            self.layout = self.project
+            self.schematic = self.project
+            layname = os.path.splitext(os.path.split(self.layout)[1])[0]
+            self.toppane.title2_frame.layout_select.config(text = layname)
+            schemname = os.path.splitext(os.path.split(self.schematic)[1])[0]
+            self.toppane.title2_frame.schem_select.config(text = schemname)
+
+            # Update schematic button
+            if os.path.splitext(self.schematic)[1] == '.v':
+                self.toppane.title2_frame.schem_label.config(text = 'Verilog netlist:')
+            else:
+                self.toppane.title2_frame.schem_label.config(text = 'Schematic netlist:')
+
+            # Update layout button
+            if os.path.splitext(self.layout)[1] == '.mag':
+                self.toppane.title2_frame.schem_label.config(text = 'Layout:')
+            else:
+                self.toppane.title2_frame.schem_label.config(text = 'Layout netlist:')
+
+            # If there is a comparison file that post-dates both netlists, load it.
+            self.check_lvs()
+        return True
+
+    def check_layout_out_of_date(self, spipath, layoutpath):
+        # Check if a netlist (spipath) is out-of-date relative to the layouts
+        # (layoutpath).  Need to read the netlist and check all of the subcells.
+        need_capture = False
+        if not os.path.isfile(spipath):
+            return True
+        if os.path.isfile(layoutpath):
+            spi_statbuf = os.stat(spipath)
+            lay_statbuf = os.stat(layoutpath)
+            if spi_statbuf.st_mtime < lay_statbuf.st_mtime:
+                # netlist exists but is out-of-date
+                need_capture = True
+            else:
+                # only found that the top-level-layout is older than the
+                # netlist.  Now need to read the netlist, find all subcircuits,
+                # and check those dates, too.
+                layoutdir = os.path.split(layoutpath)[0]
+                subrex = re.compile('^[^\*]*[ \t]*.subckt[ \t]+([^ \t]+).*$', re.IGNORECASE)
+                with open(spipath, 'r') as ifile:
+                    duttext = ifile.read()
+ 
+                dutlines = duttext.replace('\n+', ' ').splitlines()
+                for line in dutlines:
+                    lmatch = subrex.match(line)
+                    if lmatch:
+                        subname = lmatch.group(1)
+                        sublayout = layoutdir + '/' + subname + '.mag'
+                        # subcircuits that cannot be found in the current directory are
+                        # assumed to be library components and therefore never out-of-date.
+                        if os.path.exists(sublayout):
+                            sub_statbuf = os.stat(sublayout)
+                            if spi_statbuf.st_mtime < lay_statbuf.st_mtime:
+                                # netlist exists but is out-of-date
+                                need_capture = True
+                                break
+        return need_capture
+
+    def check_schematic_out_of_date(self, spipath, schempath):
+        # Check if a netlist (spipath) is out-of-date relative to the schematics
+        # (schempath).  Need to read the netlist and check all of the subcells.
+        need_capture = False
+        if not os.path.isfile(spipath):
+            return True
+        if os.path.isfile(schempath):
+            spi_statbuf = os.stat(spipath)
+            sch_statbuf = os.stat(schempath)
+            if spi_statbuf.st_mtime < sch_statbuf.st_mtime:
+                # netlist exists but is out-of-date
+                need_capture = True
+            else:
+                # only found that the top-level-schematic is older than the
+                # netlist.  Now need to read the netlist, find all subcircuits,
+                # and check those dates, too.
+                schemdir = os.path.split(schempath)[0]
+                subrex = re.compile('^[^\*]*[ \t]*.subckt[ \t]+([^ \t]+).*$', re.IGNORECASE)
+                with open(spipath, 'r') as ifile:
+                    duttext = ifile.read()
+ 
+                dutlines = duttext.replace('\n+', ' ').splitlines()
+                for line in dutlines:
+                    lmatch = subrex.match(line)
+                    if lmatch:
+                        subname = lmatch.group(1)
+                        # NOTE: Electric uses library:cell internally to track libraries,
+                        # and maps the ":" to "__" in the netlist.  Not entirely certain that
+                        # the double-underscore uniquely identifies the library:cell. . .
+                        librex = re.compile('(.*)__(.*)', re.IGNORECASE)
+                        lmatch = librex.match(subname)
+                        if lmatch:
+                            elecpath = os.path.split(os.path.split(schempath)[0])[0]
+                            libname = lmatch.group(1)
+                            subschem = elecpath + '/' + libname + '.delib/' + lmatch.group(2) + '.sch'
+                        else:
+                            libname = {}
+                            subschem = schemdir + '/' + subname + '.sch'
+                        # subcircuits that cannot be found in the current directory are
+                        # assumed to be library components and therefore never out-of-date.
+                        if os.path.exists(subschem):
+                            sub_statbuf = os.stat(subschem)
+                            if spi_statbuf.st_mtime < sub_statbuf.st_mtime:
+                                # netlist exists but is out-of-date
+                                need_capture = True
+                                break
+                        # mapping of characters to what's allowed in SPICE makes finding
+                        # the associated schematic file a bit difficult.  Requires wild-card
+                        # searching.
+                        elif libname:
+                            restr = lmatch.group(2) + '.sch'
+                            restr = restr.replace('.', '\.')
+                            restr = restr.replace('_', '.')
+                            schrex = re.compile(restr, re.IGNORECASE)
+                            libpath = elecpath + '/' + libname + '.delib'
+                            if os.path.exists(libpath):
+                                liblist = os.listdir(libpath)
+                                for file in liblist:
+                                    lmatch = schrex.match(file)
+                                    if lmatch:
+                                        subschem = libpath + '/' + file
+                                        sub_statbuf = os.stat(subschem)
+                                        if spi_statbuf.st_mtime < sch_statbuf.st_mtime:
+                                            # netlist exists but is out-of-date
+                                            need_capture = True
+                                        break
+        return need_capture
+
+    def check_lvs(self):
+        # If both netlists exist, and comp.json is more recent than both, then
+        # load LVS results from comp.json
+        project_path = self.rootpath
+        project_name = self.project
+        layout_path = project_path + '/layout/' + project_name + '.spice'
+        net_path = project_path + '/netlist/' + project_name + '.spice'
+        comp_path = project_path + '/layout/comp.json'
+
+        if os.path.exists(layout_path) and os.path.exists(net_path) and os.path.exists(comp_path):
+            magtime = os.stat(layout_path).st_mtime
+            schemtime = os.stat(net_path).st_mtime
+            comptime = os.stat(comp_path).st_mtime
+            if comptime > magtime and comptime > schemtime:
+                print("Loading LVS results from file.")
+                self.generate(comp_path)
+
+    def generate_layout_netlist(self, layout_path, layout_src, project_path):
+        # Does layout netlist exist and is it current?
+        if self.check_layout_out_of_date(layout_path, layout_src):
+            print('Generating layout netlist.')
+            self.update_idletasks()
+            mproc = subprocess.Popen(['magic', '-dnull', '-noconsole',
+			self.layout], stdin = subprocess.PIPE, stdout = subprocess.PIPE,
+			stderr = subprocess.PIPE, cwd = project_path + '/layout',
+			universal_newlines = True)
+            mproc.stdin.write("select top cell\n")
+            mproc.stdin.write("expand\n")
+            mproc.stdin.write("extract all\n")
+            mproc.stdin.write("ext2spice hierarchy on\n")
+            mproc.stdin.write("ext2spice format ngspice\n")
+            mproc.stdin.write("ext2spice scale off\n")
+            mproc.stdin.write("ext2spice renumber off\n")
+            mproc.stdin.write("ext2spice subcircuit top auto\n")
+            mproc.stdin.write("ext2spice cthresh infinite\n")
+            mproc.stdin.write("ext2spice rthresh infinite\n")
+            mproc.stdin.write("ext2spice blackbox on\n")
+            mproc.stdin.write("ext2spice -o " + self.layout + ".spice\n")
+            mproc.stdin.write("quit -noprompt\n")
+            magicout = mproc.communicate()[0]
+            self.printwarn(magicout)
+            if mproc.returncode != 0:
+                print('Failure to generate new layout netlist.')
+                return False
+
+            # Move .spice netlist to project_dir/netlist/lvs/
+            shutil.move(project_path + '/layout/' + self.layout + '.spice', layout_path)
+            # Remove extraction files
+            for file in os.listdir(project_path + '/layout'):
+                if os.path.splitext(file)[1] == '.ext':
+                    os.remove(project_path + '/layout/' + file)
+        else:
+            print('Layout netlist is up-to-date, not regenerating.')
+        return True
+
+    def run_lvs(self, value):
+        # "value" is ignored (?)
+
+        # Check if netlists exist and are current;  otherwise create them.
+        # Then run LVS.
+
+        project_path = self.rootpath
+        project_name = self.project
+
+        # Diagnostic:
+        print('project_name is ' + project_name)
+        print('project_path is ' + project_path)
+        print('self.layout is ' + self.layout)
+        print('self.schematic is ' + self.schematic)
+        print('self.lvs_setup is ' + self.lvs_setup)
+
+        has_vlog = False
+        vlog_path = project_path + '/verilog/' + project_name + '.v'
+
+        if os.path.isfile(self.layout):
+            layout_path = self.layout
+            layout_src = None
+        else:
+            layout_path = project_path + '/netlist/lvs/' + self.layout + '.spice'
+            layout_src = project_path + '/layout/' + self.layout + '.mag'
+
+        comp_dir = os.path.split(layout_path)[0]
+        comp_path = comp_dir + '/comp.json'
+
+        if os.path.isfile(self.schematic):
+            net_path = self.schematic
+        else:
+            net_path = project_path + '/netlist/schem/' + self.schematic + '.spice'
+
+        # Does the setup file exist (this is optional)?
+        if self.lvs_setup == '' and not os.path.isfile('setup.tcl'):
+            print('No technology setup file selected.')
+        elif not os.path.isfile(self.lvs_setup):
+            print("Can't find technology setup file " + self.lvs_setup)
+
+        # Does schematic netlist exist?
+        if not os.path.isfile(vlog_path) and not os.path.isfile(net_path):
+            print('Error:  No schematic netlist or verilog netlist.')
+            return
+
+        # Does LVS netlist subdirectory exist?
+        if os.path.exists(project_path + '/netlist'):
+            if not os.path.exists(project_path + '/netlist/lvs'):
+                os.makedirs(project_path + '/netlist/lvs')
+
+        # Does layout netlist exist and is it current?
+        if layout_src:
+            if not self.generate_layout_netlist(layout_path, layout_src, project_path):
+                return False
+
+        # Final checks
+        if not os.path.isfile(layout_path):
+            print('Error:  No netlist generated from magic.')
+            return
+
+        else:
+            # Read in netlist and convert commas from [X,Y] arrays to vertical bars
+            # as something that can be converted back as necessary.  ngspice treats
+            # commas as special characters for some reason.
+            with open(layout_path) as ifile:
+                spitext = ifile.read()
+
+        # Check the netlist to see if the cell to match is a subcircuit.  If
+        # not, then assume it is the top level.
+
+        layoutcell = os.path.splitext(os.path.split(self.layout)[1])[0]
+        is_subckt = False
+        subname = None
+        subrex = re.compile('^[^\*]*[ \t]*.subckt[ \t]+([^ \t]+).*$', re.IGNORECASE)
+        dutlines = spitext.replace('\n+', ' ').splitlines()
+        for line in dutlines:
+            lmatch = subrex.match(line)
+            if lmatch:
+                subname = lmatch.group(1)
+                if subname == layoutcell:
+                    is_subckt = True
+                    break
+
+        if is_subckt:
+            layout_arg = self.layout + ' ' + layoutcell
+            layout_text = '"' + layout_arg + '"'
+        elif subname:
+            layout_arg = self.layout + ' ' + subname
+            layout_text = '"' + layout_arg + '"'
+        else:
+            layout_arg = layout_path
+            layout_text = layout_arg
+
+        if has_vlog:
+            schem_arg = vlog_path + ' ' + self.schematic
+        else:
+            # Final checks
+            if not os.path.isfile(net_path):
+                print('Error:  No netlist from schematic.')
+                return
+
+            with open(net_path) as ifile:
+                spitext = ifile.read()
+
+            # Check the netlist to see if the cell to match is a subcircuit.  If
+            # not, then assume it is the top level.
+
+            schemcell = os.path.splitext(os.path.split(self.schematic)[1])[0]
+            subname = None
+            is_subckt = False
+            subrex = re.compile('^[^\*]*[ \t]*.subckt[ \t]+([^ \t]+).*$', re.IGNORECASE)
+            dutlines = spitext.replace('\n+', ' ').splitlines()
+            for line in dutlines:
+                lmatch = subrex.match(line)
+                if lmatch:
+                    subname = lmatch.group(1)
+                    if subname == schemcell:
+                        is_subckt = True
+                        break
+
+            if is_subckt:
+                schem_arg = self.schematic + ' ' + schemcell
+                schem_text = '"' + schem_arg + '"'
+            elif subname:
+                schem_arg = self.schematic + ' ' + subname
+                schem_text = '"' + schem_arg + '"'
+            else:
+                schem_arg = net_path
+                schem_text = schem_arg
+
+        # Remove any previous comparison output file
+        comp_out_path = os.path.splitext(comp_path)[0] + '.out'
+        if os.path.exists(comp_out_path):
+            os.remove(comp_out_path)
+
+        # Run netgen as subprocess
+        print('Running: netgen -batch lvs ' + layout_text + 
+		' ' + schem_text + ' ' + self.lvs_setup + ' ' + comp_out_path +
+		' -json -blackbox')
+        # Note: Because arguments to subprocess are list items, the {filename cell}
+        # pair does *not* have to be quoted or braced.  Doing so causes a parse
+        # error.
+        self.lvsproc = subprocess.Popen(['netgen', '-batch', 'lvs',
+		layout_arg, schem_arg,
+		self.lvs_setup, comp_out_path, '-json', '-blackbox'],
+		cwd=comp_dir,
+		stdout=subprocess.PIPE, stderr=subprocess.PIPE, bufsize=0)
+        # This is largely unnecessary as netgen usually runs to completion very quickly.
+        self.watchclock(comp_path)
+
+    def watchclock(self, filename):
+        if self.lvsproc == None:
+            return
+
+        lvs_status = self.lvsproc.poll()
+        sresult = select.select([self.lvsproc.stdout, self.lvsproc.stderr], [], [], 0)[0]
+        if self.lvsproc.stdout in sresult:
+            outstring = self.lvsproc.stdout.readline().decode().strip()
+            self.logprint(outstring, doflush=True)
+            print(outstring)
+        elif self.lvsproc.stderr in sresult:
+            errstring = self.lvsproc.stderr.readline().decode().strip()
+            self.logprint(errstring, doflush = True)
+            print(errstring, file=sys.stderr)
+
+        if lvs_status != None:
+            print("netgen LVS exited with status " + str(lvs_status))
+            self.lvsproc = None
+            if lvs_status != 0:
+                print('Errors encountered in LVS.')
+                self.logprint('Errors in LVS, lvs status = ' + str(lvs_status), doflush=True)
+            # Done;  now read comp.json and fill the treeview listbox.
+            self.generate(filename)
+        else:
+            self.after(500, lambda: self.watchclock(filename))
+
+    # Generate display from "comp.out" file (json file now preferred)
+
+    def generate_orig(self, lvspath):
+        lefttext = []
+        righttext = []
+        print("Reading LVS output file " + lvspath)
+        if os.path.exists(lvspath):
+            with open(lvspath, 'r') as ifile:
+                lvslines = ifile.read().splitlines()
+            for line in lvslines:
+                if '|' in line:
+                    # parts = line.split('|')
+                    # lefttext.append(parts[0])
+                    # righttext.append(parts[1])
+                    lefttext.append(line[0:42].strip())
+                    righttext.append(line[44:].strip())
+                else:
+                    lefttext.append(line)
+                    righttext.append('')
+            # Populate treeview with text
+            self.toppane.lvsreport.repopulate(lefttext, righttext)
+ 
+        else:
+            print("Error:  No output file generated from LVS.")
+
+    # Generate output from LVS report JSON file comp.json
+
+    def generate(self, lvspath):
+        lefttext = []
+        righttext = []
+        print("Reading LVS output file " + lvspath)
+        if os.path.exists(lvspath):
+            with open(lvspath, 'r') as ifile:
+                self.lvsdata = json.load(ifile)
+
+            # Populate treeview with text
+            self.toppane.lvsreport.json_repopulate(self.lvsdata)
+ 
+        else:
+            print("Error:  No output file generated from LVS.")
+
+    def findrecord(self, value):
+        print("Unimplemented function")
+
+    def findrecord_test(self, value):
+        # Check if socket is defined;  if not, attempt to open one
+        if not self.msock:
+            try:
+                self.msock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            except:
+                 print("No response from layout tool.")
+
+            if self.msock:
+                self.msock.connect(("0.0.0.0", 12946))
+                self.msock.setblocking(False)
+        if self.msock:
+            # Pull name of net or device from 'value'
+            # This is a test:
+            self.msock.sendall(b'box 0 0 100 100\r\n')
+
+if __name__ == '__main__':
+    options = []
+    arguments = []
+    for item in sys.argv[1:]:
+        if item.find('-', 0) == 0:
+            options.append(item)
+        else:
+            arguments.append(item)
+
+    root = tkinter.Tk()
+    app = LVSManager(root)
+    if arguments:
+        if len(arguments) >= 2:
+            app.set_project(arguments[0], project_name=arguments[1])
+        else:
+            app.set_project(arguments[0])
+
+    root.mainloop()
diff --git a/tcltk/netgen.tcl.in b/tcltk/netgen.tcl.in
index ba20352..2bd2e8e 100644
--- a/tcltk/netgen.tcl.in
+++ b/tcltk/netgen.tcl.in
@@ -650,7 +650,8 @@ proc netgen::lvs { name1 name2 {setupfile setup.tcl} {logfile comp.out} args} {
    puts stdout "Result: " nonewline
    netgen::log echo on
    if {$pinsgood == 0} {
-      netgen::log put "The top level cell failed pin matching.\n"
+      # NOTE:  Need to disambiguate these two cases. . .
+      netgen::log put "Cells failed matching, or top level cell failed pin matching.\n"
    } else {
       verify only
    }