Comment 3 for bug 1787810

Here's the stack trace I get:

Call stack:
[00] SCH_SCREEN::FreeDrawList() sch_screen.cpp:16
[01] SCH_SCREEN::~SCH_SCREEN() sch_screen.cpp:12
[02] SCH_SCREEN::~SCH_SCREEN() sch_screen.cpp:12
[03] SCH_SCREEN::~SCH_SCREEN() sch_screen.cpp:11
[04] SCH_SHEET::~SCH_SHEET() sch_sheet.cpp:9
[05] SCH_SHEET::~SCH_SHEET() sch_sheet.cpp:9
[06] SCH_SHEET::~SCH_SHEET() sch_sheet.cpp:8
[07] SCH_EDIT_FRAME::AppendSchematic() memory:255
[08] SCH_EDIT_FRAME::OnAppendProject(wxCommandEvent&) files-io.cpp:64

Application: kicad
Version: (6.0.0-rc1-dev-354-gddbf8e3ff-dirty), debug build
Libraries:
    wxWidgets 3.0.4
    libcurl/7.54.0 LibreSSL/2.0.20 zlib/1.2.11 nghttp2/1.24.0
Platform: Mac OS X (Darwin 17.7.0 x86_64), 64 bit, Little endian, wxMac
Build Info:
    wxWidgets: 3.0.4 (UTF-8,STL containers,compatible with 2.8)
    Boost: 1.66.0
    Curl: 7.57.0
    Compiler: Clang 9.1.0 with C++ ABI 1002

Build settings:
    USE_WX_GRAPHICS_CONTEXT=ON
    USE_WX_OVERLAY=ON
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=OFF
    KICAD_SCRIPTING_WXPYTHON=OFF
    KICAD_SCRIPTING_ACTION_MENU=OFF
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=OFF
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON