[racket] raco exe: unknown module

Hello,

Using the latest Racket snapshot, I am getting a cryptic
error message in raco exe.
test.slon is a program written in a custom #lang.

$ racket -v
Welcome to Racket v6.1.1.8.
$ raco make test.slon
$ racket test.slon
OK
$ raco exe test.slon
require: unknown module
   module name: #<resolved-module-path:(submod 
"/opt/racket/share/pkgs/math-lib/math/private/array/typed-array-struct.rkt" 
untyped-defs #%contract-defs)>
   context...:
    /opt/racket/collects/compiler/embed.rkt:395:0: get-code
    /opt/racket/collects/compiler/../racket/private/map.rkt:64:19: loop
    /opt/racket/collects/compiler/embed.rkt:395:0: get-code
    /opt/racket/collects/compiler/../racket/private/map.rkt:64:19: loop
    /opt/racket/collects/compiler/embed.rkt:395:0: get-code
    /opt/racket/collects/compiler/../racket/private/map.rkt:64:19: loop
    /opt/racket/collects/compiler/embed.rkt:395:0: get-code
    /opt/racket/collects/compiler/../racket/private/map.rkt:64:19: loop
    /opt/racket/collects/compiler/embed.rkt:395:0: get-code
    /opt/racket/collects/compiler/../racket/private/map.rkt:64:19: loop
    /opt/racket/collects/compiler/embed.rkt:395:0: get-code
    /opt/racket/collects/compiler/../racket/private/map.rkt:64:19: loop
    /opt/racket/collects/compiler/embed.rkt:395:0: get-code
    /opt/racket/collects/compiler/../racket/private/map.rkt:64:19: loop
    /opt/racket/collects/compiler/embed.rkt:395:0: get-code
    /opt/racket/collects/compiler/../racket/private/map.rkt:64:19: loop...


I do not use any Typed Racket (not directly at least).
I am getting this error in both Windows and Linux.
Some time ago all worked fine.

What can I do to trace down the bug?



Best regards,

Dmitry