So, after several hours more of investigation, I discovered that while gdb was installed on my machine, it was not installed on the machine where we were testing. I installed it there, but the crash still occurs. The backtrace produced is quite huge - and less useful because X didn't have any of the debugging symbols in it.
here is a bit of what we are seeing. We start up the X server. It is configured to use xauth. We start up a mintty session and an xterm session. We ssh from these windows to our SPARC Solaris 9 work machines. We start up, in each window, an in-house written binary application which makes use of the Tk C libraries. If we run just 1 mintty, or just 1 xterm, that works. If we run one of each (which the developers do due to various features, etc. they wish to leverage), we often - not always - get an error of the following nature. GNU gdb (GDB) 7.3.50.20111026-cvs (cygwin-special) This GDB was configured as "i686-cygwin". ==================== Backtrace ================ Thread 25 (Thread 5368.0x1704): #0 0x775e000d in ntdll!LdrFindResource_U () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #1 0x7766f896 in ntdll!RtlQueryTimeZoneInformation () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #2 0x70d9aec6 in ?? () No symbol table info available. : and so on : Thread 24 (Thread 5368.0x1b24): #0 0x775ef8b1 in ntdll!RtlUpdateClonedSRWLock () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #1 0x775ef8b1 in ntdll!RtlUpdateClonedSRWLock () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #2 0x762f0a91 in WaitForSingleObjectEx () from /cygdrive/c/Windows/syswow64/KERNELBASE.dll No symbol table info available. #3 0x000007a4 in ?? () No symbol table info available. : and so on : Thread 23 (Thread 5368.0x1590): #0 0x775efd71 in ntdll!RtlFindSetBits () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #1 0x762f31bb in SleepEx () from /cygdrive/c/Windows/syswow64/KERNELBASE.dll No symbol table info available. #2 0x00000000 in ?? () No symbol table info available. Thread 22 (Thread 5368.0x1a20): #0 0x775f013d in ntdll!RtlEnableEarlyCriticalSectionEventCreation () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #1 0x775f013d in ntdll!RtlEnableEarlyCriticalSectionEventCreation () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #2 0x762f0bdd in WaitForMultipleObjectsEx () from /cygdrive/c/Windows/syswow64/KERNELBASE.dll : and so on : Thread 21 (Thread 5368.0x18f4): #0 0x775ef8e5 in ntdll!RtlUpdateClonedSRWLock () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #1 0x775ef8e5 in ntdll!RtlUpdateClonedSRWLock () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #2 0x762ed348 in ReadFile () from /cygdrive/c/Windows/syswow64/KERNELBASE.dll No symbol table info available. #3 0x00000794 in ?? () : and so on : many more threads and finally : Thread 1 (Thread 5368.0x1bec): #0 0x775f013d in ntdll!RtlEnableEarlyCriticalSectionEventCreation () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #1 0x775f013d in ntdll!RtlEnableEarlyCriticalSectionEventCreation () from /cygdrive/c/Windows/SysWOW64/ntdll.dll No symbol table info available. #2 0x762f0bdd in WaitForMultipleObjectsEx () from /cygdrive/c/Windows/syswow64/KERNELBASE.dll No symbol table info available. #3 0x00000003 in ?? () No symbol table info available. : and so on : Backtrace stopped: previous frame inner to this frame (corrupt stack?) ==================== Backtrace End ============ [ 3569.256] Segmentation fault at address 0x65682e91 [ 3569.256] Fatal server error: [ 3569.256] Caught signal 11 (Segmentation fault). Server aborting [ 3569.256] [ 3569.256] Server terminated with error (1). Closing log file. Note that in several of the skipped portions above there were lines such as Backtrace stopped: Not enough registers or memory available to unwind further The log file is 45K, so I didn't include it completely until I hear back that someone would find it useful -- Tcl - The glue of a new generation. http://wiki.tcl.tk/ Larry W. Virden http://www.facebook.com/lvirden/ Even if explicitly stated to the contrary, nothing in this posting should be construed as representing my employer's opinions. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://x.cygwin.com/docs/ FAQ: http://x.cygwin.com/docs/faq/