$ gdb
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(gdb) attach 7962
Attaching to process 7962
[New LWP 7973]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
0x00007fc51b4cd3bd in pthread_cond_wait@@GLIBC_2.3.2 () from /usr/lib64/libpthread.so.0
(gdb) cont
Continuing.

Thread 1 "tkscidb-beta" received signal SIGSEGV, Segmentation fault.
0x00007fc51c03f268 in HashArrayKey () from /usr/lib64/libtcl8.6.so
(gdb) bt
#0  0x00007fc51c03f268 in HashArrayKey () from /usr/lib64/libtcl8.6.so
#1  0x00007fc51c03f3c9 in CreateHashEntry () from /usr/lib64/libtcl8.6.so
#2  0x00007fc51d4f6b59 in MakeTransparentWindowExist (tkwin=0x7fc5163e1fc0, parent=2097185) at tk_busy.cpp:871
#3  0x00007fc51d4f6f26 in CreateBusy (interp=0x7fffb9d22620, tkRef=0x7fffba029690) at tk_busy.cpp:1016
#4  0x00007fc51d4f71b6 in HoldBusy (busyTablePtr=0x7fc51dd3bea0 <ScBusyObjCmd(void*, Tcl_Interp*, int, Tcl_Obj* const*)::busyTable>,
    interp=0x7fffb9d22620, windowObj=0x7fffba7c8130, configObjc=0, configObjv=0x7fffb9d27070) at tk_busy.cpp:1171
#5  0x00007fc51d4f778d in ScBusyObjCmd (clientData=0x0, interp=0x7fffb9d22620, objc=3, objv=0x7fffb9d27058) at tk_busy.cpp:1342
#6  0x00007fc51d455bd9 in safeCall (clientData=0x7fc51d4f7248 <ScBusyObjCmd(ClientData, Tcl_Interp*, int, Tcl_Obj* const*)>,
    ti=0x7fffb9d22620, objc=3, objv=0x7fffb9d27058) at tcl_base.cpp:1006
#7  0x00007fc51bf9fe36 in TclNRRunCallbacks () from /usr/lib64/libtcl8.6.so
#8  0x00007fc51cd89d84 in Ttk_InvokeEnsemble () from /usr/lib64/libtk8.6.so
#9  0x00007fc51cd9022c in WidgetInstanceObjCmd () from /usr/lib64/libtk8.6.so
#10 0x00007fc51bf9fe36 in TclNRRunCallbacks () from /usr/lib64/libtcl8.6.so
#11 0x00007fc51cd90f8a in TtkWidgetInstateCommand () from /usr/lib64/libtk8.6.so
#12 0x00007fc51cd89d84 in Ttk_InvokeEnsemble () from /usr/lib64/libtk8.6.so
#13 0x00007fc51cd9022c in WidgetInstanceObjCmd () from /usr/lib64/libtk8.6.so
#14 0x00007fc51bf9fe36 in TclNRRunCallbacks () from /usr/lib64/libtcl8.6.so
#15 0x00007fc51cd90f8a in TtkWidgetInstateCommand () from /usr/lib64/libtk8.6.so
#16 0x00007fc51cd89d84 in Ttk_InvokeEnsemble () from /usr/lib64/libtk8.6.so
#17 0x00007fc51cd9022c in WidgetInstanceObjCmd () from /usr/lib64/libtk8.6.so
#18 0x00007fc51bf9fe36 in TclNRRunCallbacks () from /usr/lib64/libtcl8.6.so
#19 0x00007fc51bfa1ccc in TclEvalEx () from /usr/lib64/libtcl8.6.so
#20 0x00007fc51bfa2503 in Tcl_EvalEx () from /usr/lib64/libtcl8.6.so
#21 0x00007fc51ccda896 in Tk_BindEvent () from /usr/lib64/libtk8.6.so
#22 0x00007fc51ccde7ef in TkBindEventProc () from /usr/lib64/libtk8.6.so
#23 0x00007fc51cce66fa in Tk_HandleEvent () from /usr/lib64/libtk8.6.so
#24 0x00007fc51cce68f1 in WindowEventProc () from /usr/lib64/libtk8.6.so
#25 0x00007fc51c069c88 in Tcl_ServiceEvent () from /usr/lib64/libtcl8.6.so
#26 0x00007fc51c069ef0 in Tcl_DoOneEvent () from /usr/lib64/libtcl8.6.so
#27 0x00007fc51cce7112 in Tk_MainLoop () from /usr/lib64/libtk8.6.so
#28 0x00007fc51ccf5ccb in Tk_MainEx () from /usr/lib64/libtk8.6.so
#29 0x00007fc51d44cd65 in main (argc=2, argv=0x7fffc08bd0d8) at tkscidb.cpp:110
(gdb)