I can confirm this. It does not happen in *every* case, but happened for me on a new document.

Don't have time to go fixing this at the moment, but here is a backtrace with more info:

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000021 in ?? ()
(gdb) bt full
#0  0x0000000000000021 in ?? ()
No symbol table info available.
#1  0x00007fffe72dd3c4 in SCH_FIND_COLLECTOR::GetText (this=0x7af1b8) at /home/cmp/git/kicad/eeschema/sch_collectors.cpp:433
        data = {m_position = {x = 5525, y = 4028}, m_sheetPath = {static npos = 18446744073709551615, m_impl = L"/", m_convertedToChar = {m_str = 0x0, m_len = 140737073960963}}, m_parent = 0x1763790}
        foundItem = 0x154c110
        msg = {static npos = 18446744073709551615, m_impl = L"", m_convertedToChar = {m_str = 0x0, m_len = 140737488340680}}
#2  0x00007fffe7241ad4 in SCH_EDIT_FRAME::updateFindReplaceView (this=0x7ae8e0, aEvent=...) at /home/cmp/git/kicad/eeschema/find.cpp:430
        sheet = 0x7fffffffc680
        item = 0x380
        msg = {static npos = 18446744073709551615, m_impl = L"", m_convertedToChar = {m_str = 0x0, m_len = 140737070429452}}
        schematic = {m_list = 0x737120, m_count = 1, m_index = 1, m_isRootSheet = true, m_currList = {m_sheets = {0x8371e0, 0x0 <repeats 31 times>}, m_numSheets = 0}}
        data = {m_position = {x = 5525, y = 4028}, m_sheetPath = {static npos = 18446744073709551615, m_impl = L"/", m_convertedToChar = {m_str = 0x0, m_len = 0}}, m_parent = 0x1763790}
        warpCursor = true
#3  0x00007fffe72417cb in SCH_EDIT_FRAME::OnFindSchematicItem (this=0x7ae8e0, aEvent=...) at /home/cmp/git/kicad/eeschema/find.cpp:346
        itemPosition = {x = 0, y = 0}
        schematic = {m_list = 0x831990, m_count = 1, m_index = 1, m_isRootSheet = true, m_currList = {m_sheets = {0x8371e0, 0x0 <repeats 31 times>}, m_numSheets = 0}}
        msg = {static npos = 18446744073709551615, m_impl = L"", m_convertedToChar = {m_str = 0x0, m_len = 9806416}}
        searchCriteria = {<wxFindReplaceData> = {<wxObject> = {<No data fields>}, m_Flags = 2227, m_FindWhat = {static npos = 18446744073709551615, m_impl = L"U?A", m_convertedToChar = {m_str = 0x0, m_len = 0}}, m_ReplaceWith = {
              static npos = 18446744073709551615, m_impl = L"", m_convertedToChar = {m_str = 0x0, m_len = 0}}}, <No data fields>}
        data = {m_position = {x = -1, y = -1}, m_sheetPath = {static npos = 18446744073709551615, m_impl = L"", m_convertedToChar = {m_str = 0x0, m_len = 1296236544}}, m_parent = 0x0}
#4  0x00007fffe7333592 in SCH_EDIT_FRAME::OnFindDialogClose (this=0x7ae8e0, event=...) at /home/cmp/git/kicad/eeschema/schframe.cpp:887
No locals.
#5  0x00007ffff631893e in wxAppConsoleBase::CallEventHandler(wxEvtHandler*, wxEventFunctor&, wxEvent&) const () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#6  0x00007ffff64b02e8 in wxEvtHandler::ProcessEventIfMatchesId(wxEventTableEntryBase const&, wxEvtHandler*, wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#7  0x00007ffff64b03eb in wxEventHashTable::HandleEvent(wxEvent&, wxEvtHandler*) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#8  0x00007ffff64b07a8 in wxEvtHandler::TryHereOnly(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#9  0x00007fffe73a465d in EDA_BASE_FRAME::ProcessEvent (this=0x7ae8e0, aEvent=...) at /home/cmp/git/kicad/common/basicframe.cpp:164
No locals.
#10 0x00007ffff64b05a3 in wxEvtHandler::DoTryChain(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#11 0x00007ffff64b0895 in wxEvtHandler::ProcessEvent(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#12 0x00007fffe7221f69 in DIALOG_SCH_FIND::SendEvent (this=0x1550780, aEventType=@0x7ffff724dfc0: 10133) at /home/cmp/git/kicad/eeschema/dialogs/dialog_schematic_find.cpp:249
        event = <incomplete type>
        flags = 2227
#13 0x00007fffe7222833 in DIALOG_SCH_FIND::OnCancel (this=0x1550780, aEvent=...) at /home/cmp/git/kicad/eeschema/dialogs/dialog_schematic_find.cpp:176
No locals.
#14 0x00007ffff631893e in wxAppConsoleBase::CallEventHandler(wxEvtHandler*, wxEventFunctor&, wxEvent&) const () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#15 0x00007ffff64b02e8 in wxEvtHandler::ProcessEventIfMatchesId(wxEventTableEntryBase const&, wxEvtHandler*, wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#16 0x00007ffff64b06de in wxEvtHandler::SearchDynamicEventTable(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#17 0x00007ffff64b076e in wxEvtHandler::TryHereOnly(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#18 0x00007ffff64b0833 in wxEvtHandler::ProcessEventLocally(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#19 0x00007ffff64b0895 in wxEvtHandler::ProcessEvent(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#20 0x00007ffff6d4f5e4 in wxDialogBase::EmulateButtonClickIfPresent(int) () from /usr/lib/libwx_gtk2u_core-3.0.so.0
No symbol table info available.
#21 0x00007ffff6d4f68e in wxDialogBase::SendCloseButtonClickEvent() () from /usr/lib/libwx_gtk2u_core-3.0.so.0
No symbol table info available.
#22 0x00007ffff6d4f708 in wxDialogBase::OnCharHook(wxKeyEvent&) () from /usr/lib/libwx_gtk2u_core-3.0.so.0
No symbol table info available.
#23 0x00007ffff631893e in wxAppConsoleBase::CallEventHandler(wxEvtHandler*, wxEventFunctor&, wxEvent&) const () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#24 0x00007ffff64b02e8 in wxEvtHandler::ProcessEventIfMatchesId(wxEventTableEntryBase const&, wxEvtHandler*, wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#25 0x00007ffff64b03eb in wxEventHashTable::HandleEvent(wxEvent&, wxEvtHandler*) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#26 0x00007ffff64b07a8 in wxEvtHandler::TryHereOnly(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#27 0x00007ffff64b0833 in wxEvtHandler::ProcessEventLocally(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
---Type <return> to continue, or q <return> to quit---
No symbol table info available.
#28 0x00007ffff64b0895 in wxEvtHandler::ProcessEvent(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#29 0x00007ffff6e517a8 in wxWindowBase::TryAfter(wxEvent&) () from /usr/lib/libwx_gtk2u_core-3.0.so.0
No symbol table info available.
#30 0x00007ffff64b05f7 in wxEvtHandler::SafelyProcessEvent(wxEvent&) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#31 0x00007ffff6c5f4fe in ?? () from /usr/lib/libwx_gtk2u_core-3.0.so.0
No symbol table info available.
#32 0x00007ffff33f490f in ?? () from /usr/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#33 0x00007ffff2dcc2f5 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#34 0x00007ffff2dde02c in ?? () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#35 0x00007ffff2de6195 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#36 0x00007ffff2de68ef in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#37 0x00007ffff350bbac in ?? () from /usr/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#38 0x00007ffff351f6bb in gtk_window_propagate_key_event () from /usr/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#39 0x00007ffff6c4bf88 in ?? () from /usr/lib/libwx_gtk2u_core-3.0.so.0
No symbol table info available.
#40 0x00007ffff33f490f in ?? () from /usr/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#41 0x00007ffff2dcc2f5 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#42 0x00007ffff2dde02c in ?? () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#43 0x00007ffff2de6195 in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#44 0x00007ffff2de68ef in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
No symbol table info available.
#45 0x00007ffff350bbac in ?? () from /usr/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#46 0x00007ffff33f312f in gtk_propagate_event () from /usr/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#47 0x00007ffff33f34eb in gtk_main_do_event () from /usr/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#48 0x00007ffff30682cc in ?? () from /usr/lib/libgdk-x11-2.0.so.0
No symbol table info available.
#49 0x00007ffff20ab9fd in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#50 0x00007ffff20abce0 in ?? () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#51 0x00007ffff20ac002 in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
No symbol table info available.
#52 0x00007ffff33f2467 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0
No symbol table info available.
#53 0x00007ffff6c2c485 in wxGUIEventLoop::DoRun() () from /usr/lib/libwx_gtk2u_core-3.0.so.0
No symbol table info available.
#54 0x00007ffff635dc53 in wxEventLoopBase::Run() () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#55 0x00007ffff631cb46 in wxAppConsoleBase::MainLoop() () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#56 0x00000000004228cb in APP_SINGLE_TOP::OnRun (this=0x72c850) at /home/cmp/git/kicad/common/single_top.cpp:173
        ret = -1
        e = @0x7ffff7fac000: {_vptr.exception = 0x7ffff62ad000}
        ioe = @0x7ffff62beae0: {_vptr$IO_ERROR = 0xc00120000cefa, errorText = {static npos = 18446744073709551615, m_impl = <error reading variable: Cannot access memory at address 0x105c38>, m_convertedToChar = {
              m_str = 0xbab <error: Cannot access memory at address 0xbab>, m_len = 3377777030039948}}}
#57 0x00007ffff63b38f0 in wxEntry(int&, wchar_t**) () from /usr/lib/libwx_baseu-3.0.so.0
No symbol table info available.
#58 0x000000000041bf26 in main (argc=1, argv=0x7fffffffe778) at /home/cmp/git/kicad/common/single_top.cpp:210
No locals.