Well, I decided to take the plunge and try the VMMaker again.
I followed the instructions on the Swiki; got the following change sets:

ConsolidateTo4744-JMM.4.cs
VMMaker-3-2-version5.5.cs

then got the entire squeak and CVSROOT trees from CVS.

Then I started up a 3.2g-4743 image, loaded in the change sets, set up some 
plugins as internal and some external, and generated sources into a clean 
squeak/src directory. I compiled all the plugins that I could.

In a clean build directory, I ran configure and make. Despite lots of 
warnings, everything compiled OK.

Then I did a make install as root.

However, when I run the new VM, I can't get it to start. This happens:

Error: Cannot truncate this number
7 March 2002 9:45:20 am

VM: unix - Squeak3.2gamma of 15 January 2002 [latest update: #4743]
Image: Squeak3.2gamma [latest update: #4743]

Float(Object)>>error:
	Receiver: NaN
	Arguments and temporary variables: 
		aString: 	'Cannot truncate this number'
	Receiver's instance variables: 
NaN
Float>>truncated
	Receiver: NaN
	Arguments and temporary variables: 

	Receiver's instance variables: 
NaN
Float>>rounded
	Receiver: NaN
	Arguments and temporary variables: 

	Receiver's instance variables: 
NaN
Color>>setRed:green:blue:
	Receiver: <<error during printing>>
	Arguments and temporary variables: 
		r: 	NaN
		g: 	NaN
		b: 	NaN
	Receiver's instance variables: 
		rgb: 	nil
		cachedDepth: 	nil
		cachedBitPattern: 	nil

--- The rest of the stack ---
Color class>>r:g:b:
Color class>>r:g:b:alpha:
Color>>alphaMixed:with:
Color>>lighter
SystemWindow>>setStripeColorsFrom:
SystemWindow>>activate
SystemWindow class>>noteTopWindowIn:
PasteUpMorph>>install
AutoStart class>>checkForUpdates
AutoStart class>>startUp
AutoStart class(Behavior)>>startUp:
[] in SystemDictionary>>send:toClassesNamedIn:with:
OrderedCollection>>do:
SystemDictionary>>send:toClassesNamedIn:with:
SystemDictionary>>processStartUpList:
SystemDictionary>>snapshot:andQuit:embedded:
SystemDictionary>>snapshot:andQuit:
TheWorldMenu>>saveAndQuit
TheWorldMenu>>doMenuItem:with:
[] in MenuItemMorph>>invokeWithEvent:
BlockContext>>ensure:
CursorWithMask(Cursor)>>showWhile:
MenuItemMorph>>invokeWithEvent:
MenuItemMorph>>mouseUp:
MenuItemMorph>>handleMouseUp:
MouseButtonEvent>>sentTo:
MenuItemMorph(Morph)>>handleEvent:
MorphicEventDispatcher>>dispatchDefault:with:
MorphicEventDispatcher>>dispatchEvent:with:
MenuItemMorph(Morph)>>processEvent:using:
MorphicEventDispatcher>>dispatchDefault:with:
MorphicEventDispatcher>>dispatchEvent:with:
MenuMorph(Morph)>>processEvent:using:
MenuMorph(Morph)>>processEvent:
MenuMorph>>handleFocusEvent:
[] in HandMorph>>sendFocusEvent:to:clear:
PasteUpMorph>>becomeActiveDuring:
HandMorph>>sendFocusEvent:to:clear:
HandMorph>>sendEvent:focus:clear:
HandMorph>>sendMouseEvent:
HandMorph>>handleEvent:
HandMorph>>processEvents
[] in WorldState>>doOneCycleNowFor:
Array(SequenceableCollection)>>do:
WorldState>>handsDo:
WorldState>>doOneCycleNowFor:
WorldState>>doOneCycleFor:
PasteUpMorph>>doOneCycle
[] in Project class>>spawnNewProcess
[] in BlockContext>>newProcess

So now what do I do?
[this is under Linux, if it matters].

The same image runs using the old VM, in the same directory.

Thanks,
-- 
Ned Konz
currently: Stanwood, WA
email:     ned at bike-nomad.com
homepage:  http://bike-nomad.com