Segfault on Tcl_NewIntObj()

Process 61663 stopped
* thread #1: tid = 0xc936a, 0x00000001001ca4e9 irmsde`TclThreadAllocObj + 345 at tclThreadAlloc.c:588, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x20)
    frame #0: 0x00000001001ca4e9 irmsde`TclThreadAllocObj + 345 at tclThreadAlloc.c:588
   585 	     */
   586 	
   587 	    objPtr = cachePtr->firstObjPtr;
-> 588 	    cachePtr->firstObjPtr = objPtr->internalRep.twoPtrValue.ptr1;
   589 	    cachePtr->numObjects--;
   590 	    return objPtr;
   591 	}
(lldb) bt
* thread #1: tid = 0xc936a, 0x00000001001ca4e9 irmsde`TclThreadAllocObj + 345 at tclThreadAlloc.c:588, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x20)
  * frame #0: 0x00000001001ca4e9 irmsde`TclThreadAllocObj + 345 at tclThreadAlloc.c:588
    frame #1: 0x0000000100199ac5 irmsde`Tcl_NewIntObj(intValue=0) + 21 at tclObj.c:2396
    frame #2: 0x0000000103c0050f tcl_tBw36C`SimNode_StructAddLocation(interp=0x0000000102808010, p=0x0000000107f80610, pValueDict=0x00000001103d5730) + 1359 at cstruct_simnode.c:1311
    frame #3: 0x0000000103bfffb6 tcl_tBw36C`SimNode_StructToDict(interp=0x0000000102808010, p=0x0000000107f80610, virtual=1) + 342 at cstruct_simnode.c:980
    frame #4: 0x0000000103c00a2e tcl_tBw36C`SimNode_nodeeval(interp=0x0000000102808010, p=0x0000000107f80610, body=0x00000001092f6240, writeback=0) + 46 at cstruct_simnode.c:1197
    frame #5: 0x0000000103c0b33b tcl_tBw36C`SimNode_method_foreach(simulator=0x0000000103c3cc08, interp=0x0000000102808010, objc=2, objv=0x0000000111928fa0) + 219 at cstruct_simnode.c:3306
    frame #6: 0x000000010003d751 irmsde`Dispatch(data=0x00000001119a6728, interp=0x0000000102808010, result=0) + 129 at tclBasic.c:4359
    frame #7: 0x000000010003927c irmsde`TclNRRunCallbacks(interp=0x0000000102808010, result=0, rootPtr=0x00000001066f5d40) + 172 at tclBasic.c:4392
    frame #8: 0x000000010003ba40 irmsde`TclEvalObjEx(interp=0x0000000102808010, objPtr=0x0000000109153bb0, flags=131072, invoker=0x0000000000000000, word=0) + 96 at tclBasic.c:5958
    frame #9: 0x0000000100038923 irmsde`Tcl_EvalObjEx(interp=0x0000000102808010, objPtr=0x0000000109153bb0, flags=131072) + 51 at tclBasic.c:5939
    frame #10: 0x0000000103e5b8bc libtk8.6.dylib`Ttk_InvokeEnsemble + 187
    frame #11: 0x0000000103e626b7 libtk8.6.dylib`WidgetInstanceObjCmd + 80
    frame #12: 0x000000010003d751 irmsde`Dispatch(data=0x00000001066f5c28, interp=0x0000000102808010, result=0) + 129 at tclBasic.c:4359
    frame #13: 0x000000010003927c irmsde`TclNRRunCallbacks(interp=0x0000000102808010, result=0, rootPtr=0x000000010914e6f0) + 172 at tclBasic.c:4392
    frame #14: 0x000000010003ba40 irmsde`TclEvalObjEx(interp=0x0000000102808010, objPtr=0x00000001090ed290, flags=0, invoker=0x0000000000000000, word=0) + 96 at tclBasic.c:5958
    frame #15: 0x0000000100038923 irmsde`Tcl_EvalObjEx(interp=0x0000000102808010, objPtr=0x00000001090ed290, flags=0) + 51 at tclBasic.c:5939
    frame #16: 0x0000000103e62f27 libtk8.6.dylib`TtkWidgetInstateCommand + 151
    frame #17: 0x0000000103e5b8bc libtk8.6.dylib`Ttk_InvokeEnsemble + 187
    frame #18: 0x0000000103e626b7 libtk8.6.dylib`WidgetInstanceObjCmd + 80
    frame #19: 0x000000010003d751 irmsde`Dispatch(data=0x000000010914db88, interp=0x0000000102808010, result=0) + 129 at tclBasic.c:4359
    frame #20: 0x000000010003927c irmsde`TclNRRunCallbacks(interp=0x0000000102808010, result=0, rootPtr=0x0000000109236010) + 172 at tclBasic.c:4392
    frame #21: 0x000000010003ba40 irmsde`TclEvalObjEx(interp=0x0000000102808010, objPtr=0x00000001098bb750, flags=0, invoker=0x0000000000000000, word=0) + 96 at tclBasic.c:5958
    frame #22: 0x0000000100038923 irmsde`Tcl_EvalObjEx(interp=0x0000000102808010, objPtr=0x00000001098bb750, flags=0) + 51 at tclBasic.c:5939
    frame #23: 0x0000000103e62f27 libtk8.6.dylib`TtkWidgetInstateCommand + 151
    frame #24: 0x0000000103e5b8bc libtk8.6.dylib`Ttk_InvokeEnsemble + 187
    frame #25: 0x0000000103e626b7 libtk8.6.dylib`WidgetInstanceObjCmd + 80
    frame #26: 0x000000010003d751 irmsde`Dispatch(data=0x0000000109236378, interp=0x0000000102808010, result=0) + 129 at tclBasic.c:4359
    frame #27: 0x000000010003927c irmsde`TclNRRunCallbacks(interp=0x0000000102808010, result=0, rootPtr=0x000000010301a560) + 172 at tclBasic.c:4392
    frame #28: 0x0000000100038f99 irmsde`Tcl_EvalObjv(interp=0x0000000102808010, objc=4, objv=0x000000010280ca20, flags=2097168) + 89 at tclBasic.c:4123
    frame #29: 0x000000010003aac8 irmsde`TclEvalEx(interp=0x0000000102808010, script=0x00007fff5fbfef08, numBytes=190, flags=131072, line=1, clNextOuter=0x0000000000000000, outerScript=0x00007fff5fbfef08) + 3288 at tclBasic.c:5261
    frame #30: 0x0000000100039de1 irmsde`Tcl_EvalEx(interp=0x0000000102808010, script=0x00007fff5fbfef08, numBytes=190, flags=131072) + 65 at tclBasic.c:4926
    frame #31: 0x0000000103db98d6 libtk8.6.dylib`Tk_BindEvent + 3870
    frame #32: 0x0000000103dbef7b libtk8.6.dylib`TkBindEventProc + 347
    frame #33: 0x0000000103dc6bf0 libtk8.6.dylib`Tk_HandleEvent + 1542
    frame #34: 0x0000000103dc7124 libtk8.6.dylib`WindowEventProc + 96
    frame #35: 0x0000000100196837 irmsde`Tcl_ServiceEvent(flags=-3) + 231 at tclNotify.c:670
    frame #36: 0x0000000100196bf7 irmsde`Tcl_DoOneEvent(flags=-3) + 183 at tclNotify.c:903
    frame #37: 0x000000010012795a irmsde`Tcl_VwaitObjCmd(clientData=0x0000000000000000, interp=0x0000000102808010, objc=2, objv=0x0000000103029660) + 234 at tclEvent.c:1405
    frame #38: 0x000000010003d751 irmsde`Dispatch(data=0x000000010301ff68, interp=0x0000000102808010, result=0) + 129 at tclBasic.c:4359
    frame #39: 0x000000010003927c irmsde`TclNRRunCallbacks(interp=0x0000000102808010, result=0, rootPtr=0x0000000000000000) + 172 at tclBasic.c:4392
    frame #40: 0x0000000100038f99 irmsde`Tcl_EvalObjv(interp=0x0000000102808010, objc=3, objv=0x000000010280c2f0, flags=2097168) + 89 at tclBasic.c:4123
    frame #41: 0x000000010003aac8 irmsde`TclEvalEx(interp=0x0000000102808010, script=0x000000010305fc10, numBytes=7930, flags=0, line=317, clNextOuter=0x0000000000000000, outerScript=0x000000010305fc10) + 3288 at tclBasic.c:5261
    frame #42: 0x0000000100181483 irmsde`Tcl_FSEvalFileEx(interp=0x0000000102808010, pathPtr=0x000000010082d030, encodingName=0x0000000000000000) + 1075 at tclIOUtil.c:1815
    frame #43: 0x000000010018cf9a irmsde`Tcl_MainEx(argc=-1, argv=0x00007fff5fbffaa0, appInitProc=0x0000000100019120, interp=0x0000000102808010) + 1274 at tclMain.c:417
    frame #44: 0x000000010001923e irmsde`main(argc=2, argv=0x00007fff5fbffa90) + 110 at tclsh_main.c:19
    frame #45: 0x00007fff8d6765c9 libdyld.dylib`start + 1
(lldb)