Comment 6 for bug 1672733

Not sure if relevant, but the footprint being queried at the time was invalid:

(gdb) f 2
(gdb) p aEntry
$9 = (FP_LOADER_THREAD::CACHE_ENTRY &) @0x7fc98d72b958: {fpid = {
    nickname = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "", <No data fields>},
    item_name = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "footprint", <No data fields>},
    revision = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "", <No data fields>}}, module = 0x0,
  status = FPS_NOT_FOUND}

(gdb) p *m_iface
$10 = {m_loaderQueue = std::deque with 0 elements, m_cachedFootprints = std::map with 2 elements = {[{
      nickname = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "", <No data fields>},
      item_name = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "footprint", <No data fields>},
      revision = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "", <No data fields>}}] = {fpid = {
        nickname = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "", <No data fields>},
        item_name = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "footprint", <No data fields>},
        revision = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "", <No data fields>}}, module = 0x0,
      status = FPS_NOT_FOUND}, [{
      nickname = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "IPC7351-Nominal", <No data fields>},
      item_name = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "CAPC1608X55", <No data fields>},
      revision = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "", <No data fields>}}] = {fpid = {
        nickname = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "IPC7351-Nominal", <No data fields>},
        item_name = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "CAPC1608X55", <No data fields>},
        revision = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "", <No data fields>}}, module = 0x7fc985cf2660,
      status = FPS_READY}}, m_current_fp = {
    nickname = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "", <No data fields>},
    item_name = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "footprint", <No data fields>},
    revision = {<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >> = "", <No data fields>}}, m_lock = {m_mutex = {m_mut = {
        __data = {__lock = 0, __count = 0, __owner = 0, __nusers = 0, __kind = 128, __spins = 0, __elision = 0, __list = {__prev = 0x0, __next = 0x0}},
        __size = '\000' <repeats 16 times>, "\200", '\000' <repeats 22 times>, __align = 0}}}}