Re: [MIT-Scheme-devel] Edwin cannot run `M-x shell' on Mac OS 10.8

[Taylor R Campbell]

   Date: Sat, 22 Jun 2013 17:03:15 -0400
   From: Rich Loveland <address@hidden>

   Do you mean a Scheme stack trace? I'm not sure how to get one. No
   error was signalled in the controlling terminal, nor did the debugger
   pop up in the terminal or in Edwin -- just the error message in an
   Edwin window.

M-x set-variable RET debug-on-internal-error RET #t RET

   I did grab some dtruss output from running Edwin and doing `M-x shell'
   again; this is the only error I found (longer version is attached):

That's not the error in question -- look for fcntl(..., F_SETFL, ...),
or the numeric value from <sys/fcntl.h> instead of F_SETFL.  It looks
like this is probably the failure:

fcntl(0x5, 0x4, 0x6)             = -1 Err#25

But I don't see the creation of file descriptor 5, unless the trace
got out of order.

(We should stop using sigprocmask so much...  The dstack abstraction
is handy, but it can be done more safely with less overhead, and
without so thoroughly cluttering system call traces.)