$ gdb attach 29
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attach: No such file or directory.
Attaching to process 29
[New LWP 32]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
0x00007f7c80cdd9f3 in futex_wait_cancelable (private=<optimized out>, expected=0, futex_word=0x7fffe7633a40)
    at ../sysdeps/unix/sysv/linux/futex-internal.h:88
88      ../sysdeps/unix/sysv/linux/futex-internal.h: No such file or directory.
(gdb) cont
Continuing.

Thread 1 "tkscidb-beta" received signal SIGSEGV, Segmentation fault.
0x00007f7c8163a518 in ?? () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
(gdb) bt
#0  0x00007f7c8163a518 in ?? () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
#1  0x00007f7c81639c69 in ?? () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
#2  0x00007f7c82cf6b89 in MakeTransparentWindowExist (tkwin=0x7f7c7c0c65f0, parent=3145758) at tk_busy.cpp:871
#3  0x00007f7c82cf6f56 in CreateBusy (interp=0x7fffe763ddf0, tkRef=0x7fffe7964ba0) at tk_busy.cpp:1016
#4  0x00007f7c82cf71e6 in HoldBusy (
    busyTablePtr=0x7f7c8353db60 <ScBusyObjCmd(void*, Tcl_Interp*, int, Tcl_Obj* const*)::busyTable>,
    interp=0x7fffe763ddf0, windowObj=0x7f7c74f85150, configObjc=0, configObjv=0x7fffe7642840) at tk_busy.cpp:1171
#5  0x00007f7c82cf77bd in ScBusyObjCmd (clientData=0x0, interp=0x7fffe763ddf0, objc=3, objv=0x7fffe7642828)
    at tk_busy.cpp:1342
#6  0x00007f7c82c55c09 in safeCall (
    clientData=0x7f7c82cf7278 <ScBusyObjCmd(ClientData, Tcl_Interp*, int, Tcl_Obj* const*)>, ti=0x7fffe763ddf0,
    objc=3, objv=0x7fffe7642828) at tcl_base.cpp:1006
#7  0x00007f7c8159b406 in TclNRRunCallbacks () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
#8  0x00007f7c823871a4 in ?? () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#9  0x00007f7c8238d61c in ?? () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#10 0x00007f7c8159b406 in TclNRRunCallbacks () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
#11 0x00007f7c8238e2da in ?? () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#12 0x00007f7c823871a4 in ?? () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#13 0x00007f7c8238d61c in ?? () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#14 0x00007f7c8159b406 in TclNRRunCallbacks () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
#15 0x00007f7c8238e2da in ?? () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#16 0x00007f7c823871a4 in ?? () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#17 0x00007f7c8238d61c in ?? () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#18 0x00007f7c8159b406 in TclNRRunCallbacks () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
#19 0x00007f7c8159bfba in ?? () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
#20 0x00007f7c8159ba63 in Tcl_EvalEx () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
#21 0x00007f7c822d5d65 in Tk_BindEvent () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#22 0x00007f7c822dc5ad in TkBindEventProc () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
---Type <return> to continue, or q <return> to quit---\
#23 0x00007f7c822e47d3 in Tk_HandleEvent () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#24 0x00007f7c822e4f80 in ?? () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#25 0x00007f7c81663787 in Tcl_ServiceEvent () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
#26 0x00007f7c816639d6 in Tcl_DoOneEvent () from /usr/lib/x86_64-linux-gnu/libtcl8.6.so
#27 0x00007f7c822e53d2 in Tk_MainLoop () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#28 0x00007f7c822f3a7a in Tk_MainEx () from /usr/lib/x86_64-linux-gnu/libtk8.6.so
#29 0x00007f7c82c4cd95 in main (argc=2, argv=0x7fffee3d6488) at tkscidb.cpp:110