Re: debug and backtrace

[Neil Jerram <neil@ossau.uklinux.net>]

ludo@gnu.org (Ludovic Courtès) writes:

> Hello!
>
> Mike Gran <spk121@yahoo.com> writes:
>
>> With the default behavior of 1.9.x, REPL debug and backtrace are broken.
>
> Indeed, it looks like the VM frames are ignored.

I've just hit this too.  So here's another example, just in case it's
useful.

Given a file testcar.scm that contains

((lambda _
   (car 1)))

1.8.x guile --debug -s testcar.scm gives a useful backtrace:

Backtrace:
In unknown file:
   ?: 0* [primitive-load "testcar.scm"]
In testcar.scm:
   2: {1}* [#<procedure #f _>]
   3: 2  [car {1}]

testcar.scm:3:4: In procedure car in expression (car 1):
testcar.scm:3:4: Wrong type (expecting pair): 1

But current (approximately speaking) Git master doesn't:

Backtrace:
In unknown file:
   ?: 0* [dynamic-wind #<program 9817a00 at ice-9/boot-9.scm:1771:18 ()> ...]
   ?: {1}* [with-fluid* #<fluid 9> #f #<program 98179a0 at ice-9/boot-9.scm:935:4 ()>]
   ?: 2* [load-compiled/vm "/home/neil/.cache/guile/ccache/1.9-0.D-LE-4/home/neil/SW/Guile/testcar.scm.go"]

ERROR: In procedure vm-debug-engine:
ERROR: Wrong type argument in position 1 (expecting pair): 1

Out of interest, is this something that has worked with the VM in the
past, and has somehow got broken?  Or is it something that hasn't been
implemented for the VM yet?  (I believe it's the former, but I'm not
sure.)

Regards,
        Neil