$ gdb /bin/sh UU/sh.exe.core
GNU gdb (GDB) Cygwin 7.9.1-1
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Reading symbols from /bin/sh...(no debugging symbols found)...done.

warning: core file may not match specified executable file.
[New Thread 0x1288]
[New Thread 0x2f38]
/wip/cygport-git/gdb/gdb-7.9.1-1.x86_64/src/gdb-7.9.1/gdb/corelow.c:542: internal-error: get_core_register_section: Assertion `core_vec' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) y

This is a bug, please report it.  For instructions, see:
<http://www.gnu.org/software/gdb/bugs/>.

/wip/cygport-git/gdb/gdb-7.9.1-1.x86_64/src/gdb-7.9.1/gdb/corelow.c:542: internal-error: get_core_register_section: Assertion `core_vec' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Create a core file of GDB? (y or n) y
*** starting debugger for pid 6248, tid 9044
*** continuing pid 6248 from debugger call (1)
Aborted (core dumped)