Errors in script running with Scsh 0.7 vs. 0.6

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Greetings scsh cognoscenti,

I've got a script throwing errors under Scsh 0.7 that runs under 0.6.
It's a word counting script that uses the `rx' package (code is below).

* Shell output

Here are the outputs from issuing the script command at the shell. The
first is for 0.7, the second for 0.6. The file is a plaintext Emacs org
file.

wc-0.7.scm < jelec-02.org
assertion-violation [ascii->char] with no handler in place: not an ASCII
code195
stack template id's: 3016 <- 1720 <- 3015 <- 914 <-  <-  <-  <-  <-  <-
 <- 1720 <-  <- 1720 <- 6624 <- 3309 <-


wc-0.6.scm < jelec-02.org
25337

* Source of the script

...is as follows (also attached in case it gets garbled -- need to set
up a plaintext email program, apologies!):

#!/usr/local/bin/scsh \
-e main -s
!#

(define wc-rx (rx (:                   ; begin a matching sequence
                   (* whitespace)      ; beginning with zero+ spaces,
                   (+ alphanumeric)    ; match 1 or more [0-9a-zA-Z]
                   (?                  ; then, optionally match:
                    (or #\' #\`)       ; - apostrophe or backtick
                    (* alphanumeric))  ; - 0 or more [0-9a-zA-Z]
                   (* whitespace))))   ; finally, 0 or more spaces end

(define (main prog+args)
  (display
   (awk (read-line) (line) ((words 0))
     (#t (+ words
            (length
             (regexp-fold-right wc-rx (lambda (m i lis)
                                        (cons (match:substring m 0) lis))
                                '() line))))))
  (newline))

* Checking `rx' sources

Finally, grepping the rx package's sources provide this output, which
I'm afraid:

>> grep "ascii->char" *
parse.scm:				((0) (values (cons (ascii->char from) loose)
parse.scm:				((1) (values `(,(ascii->char from)
parse.scm:					       ,(ascii->char to)
parse.scm:				((2) (values `(,(ascii->char from)
parse.scm:					       ,(ascii->char (+ from 1))
parse.scm:					       ,(ascii->char to)
parse.scm:					      `((,(ascii->char from) .
parse.scm:						 ,(ascii->char to))
parse.scm:	    (if (char-set-contains? cset (ascii->char i))
posixstr.scm:(define *nul* (ascii->char 0))
posixstr.scm:   ((> start end) (values (list (ascii->char c)) '())) ;
Empty range
posixstr.scm:    (values (list (ascii->char c) (ascii->char start))
posixstr.scm:    (values (list (ascii->char c) (ascii->char start)
(ascii->char end))
posixstr.scm:   (else (values (list (ascii->char c))
posixstr.scm:		 (list (cons (ascii->char start) (ascii->char end)))))))
rx-lib.scm:			       (cs cset (char-set-adjoin! cs (ascii->char i))))
scsh-read.scm:;  Ascii stuff: char->ascii, ascii->char,
ascii-whitespaces, ascii-limit
scsh-read.scm:(define bel (ascii->char 7))
scsh-read.scm:(define bs  (ascii->char  8))
scsh-read.scm:(define ff  (ascii->char 12))
scsh-read.scm:(define cr  (ascii->char 13))
scsh-read.scm:(define ht  (ascii->char  9))
scsh-read.scm:(define vt  (ascii->char 11))
scsh-read.scm:                                 (ascii->char (+ (* 64 d1)
(+ (* 8 d2) d3)))))
scsh-read.scm:                                 (ascii->char (+ (* 16 d1)
d2))))
scsh-read.scm:    (string-set! p-c-v i (p-c (ascii->char i)))))
spencer.scm:				     (cset cset (char-set-adjoin! cset (ascii->char j))))

My layman's reading of the above is that I should not do any
regexp-matching on files which contain non-ASCII characters with 0.7. Is
that correct? Although it's not clear why 0.6 works.

Any help from a kindly Scsh wizard would be much appreciated.

Best,
Rich

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#!/usr/local/bin/scsh \
-e main -s
!#

(define wc-rx (rx (:                   ; begin a matching sequence
                   (* whitespace)      ; beginning with zero or more spaces,
                   (+ alphanumeric)    ; match 1 or more chars in [0-9A-Za-z].
                   (?                  ; then, optionally match the following:
                    (or #\' #\`)       ; - apostrophe or backtick
                    (* alphanumeric))  ; - 0 or more [0-9a-zA-Z]
                   (* whitespace))))   ; finally, 0 or more spaces end the line

(define (main prog+args)
  (display
   (awk (read-line) (line) ((words 0))
     (#t (+ words
            (length
             (regexp-fold-right wc-rx (lambda (m i lis)
                                        (cons (match:substring m 0) lis))
                                '() line))))))
  (newline))

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