disambiguation menu not showing in track placement mode

Steps to reproduce:
1) choose some track under footprint or somewhere where clarification dialog displayed selecting this track.
2) Select track placement tool
3) move mouse cursor over track, press Del or backspace hotkey. Nothing happens.
4) cancel track placement tool, clarification menu appears.

Version info: today's git head,
Application: pcbnew
Version: (6.0.0-rc1-dev-1481-g5e70534-dirty), release build
Libraries:
    wxWidgets 3.0.2
Platform: Linux 4.4.0-138-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.2 (wchar_t,wx containers,compatible with 2.8) GTK+ 2.24
    Boost: 1.58.0
    Compiler: GCC 5.4.0 with C++ ABI 1009

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=OFF
    KICAD_SCRIPTING_MODULES=OFF
    KICAD_SCRIPTING_PYTHON3=OFF
    KICAD_SCRIPTING_WXPYTHON=OFF
    KICAD_SCRIPTING_WXPYTHON_PHOENIX=OFF
    KICAD_SCRIPTING_ACTION_MENU=OFF
    BUILD_GITHUB_PLUGIN=OFF
    KICAD_USE_OCE=OFF
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON