#0  MediumLock::Unlock (this=this@entry=0x700071) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Main/src-server/MediumLock.cpp:143
No locals.
#1  0x000055dc54054951 in MediumLockList::Unlock (this=this@entry=0x7faedc0008c0) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Main/src-server/MediumLock.cpp:261
        rc2 = <optimized out>
        it = {_M_node = 0x700061}
        rc = 0
#2  0x000055dc54054f68 in MediumLockList::Unlock (this=0x7faedc0008c0, this@entry=0x0) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Main/src-server/MediumLock.cpp:254
No locals.
#3  MediumLockList::Clear (this=this@entry=0x7faedc0008c0) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Main/src-server/MediumLock.cpp:210
        rc = <optimized out>
#4  0x000055dc54055054 in MediumLockList::~MediumLockList (this=0x7faedc0008c0, __in_chrg=<optimized out>) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Main/src-server/MediumLock.cpp:164
        eik = {<com::ErrorInfo> = {_vptr.ErrorInfo = 0x55dc5459e958 <vtable for com::ErrorInfoKeeper+16>, mIsBasicAvailable = false, mIsFullAvailable = false, mResultCode = 0, mResultDetail = 0, mInterfaceID = {static Empty = {static Empty = <same as static member of an already seen type>, mUuid = {au8 = '\000' <repeats 15 times>, au16 = {0, 0, 0, 0, 0, 0, 0, 0}, au32 = {0, 0, 0, 0}, au64 = {0, 0}, Gen = {u32TimeLow = 0, u16TimeMid = 0, u16TimeHiAndVersion = 0, u8ClockSeqHiAndReserved = 0 '\000', u8ClockSeqLow = 0 '\000', au8Node = "\000\000\000\000\000"}}, mGuidState = com::GUID_ZERO}, mUuid = {au8 = '\000' <repeats 15 times>, au16 = {0, 0, 0, 0, 0, 0, 0, 0}, au32 = {0, 0, 0, 0}, au64 = {0, 0}, Gen = {u32TimeLow = 0, u16TimeMid = 0, u16TimeHiAndVersion = 0, u8ClockSeqHiAndReserved = 0 '\000', u8ClockSeqLow = 0 '\000', au8Node = "\000\000\000\000\000"}}, mGuidState = com::GUID_ZERO}, mComponent = {static Empty = {static Empty = <same as static member of an already seen type>, m_bstr = 0x0}, m_bstr = 0x0}, mText = {static Empty = {static Empty = <same as static member of an already seen type>, m_bstr = 0x0}, m_bstr = 0x0}, m_pNext = 0x0, mInterfaceName = {static Empty = {static Empty = <same as static member of an already seen type>, m_bstr = 0x0}, m_bstr = 0x0}, mCalleeIID = {static Empty = {static Empty = <same as static member of an already seen type>, mUuid = {au8 = '\000' <repeats 15 times>, au16 = {0, 0, 0, 0, 0, 0, 0, 0}, au32 = {0, 0, 0, 0}, au64 = {0, 0}, Gen = {u32TimeLow = 0, u16TimeMid = 0, u16TimeHiAndVersion = 0, u8ClockSeqHiAndReserved = 0 '\000', u8ClockSeqLow = 0 '\000', au8Node = "\000\000\000\000\000"}}, mGuidState = com::GUID_ZERO}, mUuid = {au8 = '\000' <repeats 15 times>, au16 = {0, 0, 0, 0, 0, 0, 0, 0}, au32 = {0, 0, 0, 0}, au64 = {0, 0}, Gen = {u32TimeLow = 0, u16TimeMid = 0, u16TimeHiAndVersion = 0, u8ClockSeqHiAndReserved = 0 '\000', u8ClockSeqLow = 0 '\000', au8Node = "\000\000\000\000\000"}}, mGuidState = com::GUID_ZERO}, mCalleeName = {static Empty = {static Empty = <same as static member of an already seen type>, m_bstr = 0x0}, m_bstr = 0x0}, mErrorInfo = {m_p = 0x0}}, mForgot = false}
#5  0x000055dc5403096f in Medium::i_cancelMergeTo (this=0x7faf1011ffd0, aChildrenToReparent=aChildrenToReparent@entry=0x7faedc0008c0, aMediumLockList=aMediumLockList@entry=0x7faedc001f30) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Main/src-server/MediumImpl.cpp:5920
        autoCaller = {mObj = 0x7faf1011ffd0, mRC = <optimized out>, mLimited = false}
        mediumListBegin = <optimized out>
        mediumListEnd = {_M_node = 0x7faedc001f30}
#6  0x000055dc540794ba in SessionMachine::i_cancelDeleteSnapshotMedium (this=this@entry=0x7faef800dbd0, aHD=..., aSource=..., aChildrenToReparent=0x7faedc0008c0, fNeedsOnlineMerge=<optimized out>, aMediumLockList=0x7faedc001f30, aHDLockToken=..., aMachineId=..., aSnapshotId=...) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Main/src-server/SnapshotImpl.cpp:3640
No locals.
#7  0x000055dc5407f759 in SessionMachine::i_deleteSnapshotHandler (this=<optimized out>, task=...) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Main/src-server/SnapshotImpl.cpp:3217
        it = {_M_node = 0x7faedc0020f0}
        eik = {<com::ErrorInfo> = {_vptr.ErrorInfo = 0x55dc5459e958 <vtable for com::ErrorInfoKeeper+16>, mIsBasicAvailable = true, mIsFullAvailable = true, mResultCode = 2159738884, mResultDetail = 0, mInterfaceID = {static Empty = {static Empty = <same as static member of an already seen type>, mUuid = {au8 = '\000' <repeats 15 times>, au16 = {0, 0, 0, 0, 0, 0, 0, 0}, au32 = {0, 0, 0, 0}, au64 = {0, 0}, Gen = {u32TimeLow = 0, u16TimeMid = 0, u16TimeHiAndVersion = 0, u8ClockSeqHiAndReserved = 0 '\000', u8ClockSeqLow = 0 '\000', au8Node = "\000\000\000\000\000"}}, mGuidState = com::GUID_ZERO}, mUuid = {au8 = ";B\376J\340C\320\351\202\350\316\263\a\224\r\332", au16 = {16955, 19198, 17376, 59856, 59522, 46030, 37895, 55821}, au32 = {1258177083, 3922740192, 3016681602, 3658322951}, au64 = {16848040836602937915, 15712377435767892098}, Gen = {u32TimeLow = 1258177083, u16TimeMid = 17376, u16TimeHiAndVersion = 59856, u8ClockSeqHiAndReserved = 130 '\202', u8ClockSeqLow = 232 '\350', au8Node = "\316\263\a\224\r\332"}}, mGuidState = com::GUID_NORMAL}, mComponent = {static Empty = {static Empty = <same as static member of an already seen type>, m_bstr = 0x0}, m_bstr = 0x7faedc002040}, mText = {static Empty = {static Empty = <same as static member of an already seen type>, m_bstr = 0x0}, m_bstr = 0x7faedc001640}, m_pNext = 0x0, mInterfaceName = {static Empty = {static Empty = <same as static member of an already seen type>, m_bstr = 0x0}, m_bstr = 0x7faedc002080}, mCalleeIID = {static Empty = {static Empty = <same as static member of an already seen type>, mUuid = {au8 = '\000' <repeats 15 times>, au16 = {0, 0, 0, 0, 0, 0, 0, 0}, au32 = {0, 0, 0, 0}, au64 = {0, 0}, Gen = {u32TimeLow = 0, u16TimeMid = 0, u16TimeHiAndVersion = 0, u8ClockSeqHiAndReserved = 0 '\000', u8ClockSeqLow = 0 '\000', au8Node = "\000\000\000\000\000"}}, mGuidState = com::GUID_ZERO}, mUuid = {au8 = '\000' <repeats 15 times>, au16 = {0, 0, 0, 0, 0, 0, 0, 0}, au32 = {0, 0, 0, 0}, au64 = {0, 0}, Gen = {u32TimeLow = 0, u16TimeMid = 0, u16TimeHiAndVersion = 0, u8ClockSeqHiAndReserved = 0 '\000', u8ClockSeqLow = 0 '\000', au8Node = "\000\000\000\000\000"}}, mGuidState = com::GUID_ZERO}, mCalleeName = {static Empty = {static Empty = <same as static member of an already seen type>, m_bstr = 0x0}, m_bstr = 0x0}, mErrorInfo = {m_p = 0x7faedc0527e0}}, mForgot = false}
        multiLock = {<util::AutoWriteLockBase> = {<util::AutoLockBase> = {_vptr.AutoLockBase = 0x55dc545a5780 <vtable for util::AutoMultiWriteLock2+16>, m = 0x7faedc0010f0}, <No data fields>}, <No data fields>}
        mrc = {<com::FWResult> = {mRC = 2159738884}, static sCounter = 5}
        autoCaller = <optimized out>
        toDelete = {<std::__cxx11::_List_base<MediumDeleteRec, std::allocator<MediumDeleteRec> >> = {_M_impl = {<std::allocator<std::_List_node<MediumDeleteRec> >> = {<__gnu_cxx::new_allocator<std::_List_node<MediumDeleteRec> >> = {<No data fields>}, <No data fields>}, _M_node = {<std::__detail::_List_node_base> = {_M_next = 0x7faedc0020f0, _M_prev = 0x7faedc0020f0}, _M_storage = {_M_storage = "\001\000\000\000\000\000\000"}}}}, <No data fields>}
        snapshotId = {static Empty = {static Empty = <same as static member of an already seen type>, mUuid = {au8 = '\000' <repeats 15 times>, au16 = {0, 0, 0, 0, 0, 0, 0, 0}, au32 = {0, 0, 0, 0}, au64 = {0, 0}, Gen = {u32TimeLow = 0, u16TimeMid = 0, u16TimeHiAndVersion = 0, u8ClockSeqHiAndReserved = 0 '\000', u8ClockSeqLow = 0 '\000', au8Node = "\000\000\000\000\000"}}, mGuidState = com::GUID_ZERO}, mUuid = {au8 = "\314?je\224\347\204A\223z\245\332\064Y24", au16 = {16332, 25962, 59284, 16772, 31379, 55973, 22836, 13362}, au32 = {1701461964, 1099229076, 3668277907, 875714868}, au64 = {4721152933933760460, 3761166722349234835}, Gen = {u32TimeLow = 1701461964, u16TimeMid = 59284, u16TimeHiAndVersion = 16772, u8ClockSeqHiAndReserved = 147 '\223', u8ClockSeqLow = 122 'z', au8Node = "\245\332\064Y24"}}, mGuidState = com::GUID_NORMAL}
        __PRETTY_FUNCTION__ = "void SessionMachine::i_deleteSnapshotHandler(SessionMachine::DeleteSnapshotTask&)"
#8  0x000055dc54087b75 in SessionMachine::DeleteSnapshotTask::handler (this=<optimized out>) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Main/src-server/SnapshotImpl.cpp:1454
No locals.
#9  0x000055dc53f4470a in ThreadTask::taskHandlerThreadProc (pvUser=0x7faefc011f60) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Main/src-all/ThreadTask.cpp:107
        pTask = 0x7faefc011f60
#10 0x00007faf2983bbdc in rtThreadMain (pThread=pThread@entry=0x7faefc0429c0, NativeThread=NativeThread@entry=140389847676672, pszThreadName=pszThreadName@entry=0x7faefc0432a0 "DeleteSnap") at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Runtime/common/misc/thread.cpp:717
        rc = <optimized out>
#11 0x00007faf298c658b in rtThreadNativeMain (pvArgs=0x7faefc0429c0) at /build/virtualbox-2umW4l/virtualbox-5.1.26-dfsg/src/VBox/Runtime/r3/posix/thread-posix.cpp:327
        pThread = 0x7faefc0429c0
        Self = 140389847676672
        rc = <optimized out>
        __PRETTY_FUNCTION__ = "void* rtThreadNativeMain(void*)"
#12 0x00007faf29ba874a in start_thread (arg=0x7faf0f003700) at pthread_create.c:456
        __res = <optimized out>
        pd = 0x7faf0f003700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140389847676672, 6704566830758041285, 140389853468542, 140389853468543, 140389847677376, 140389847676672, -6749358711313852731, -6749423081335744827}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
        __PRETTY_FUNCTION__ = "start_thread"
#13 0x00007faf28795caf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97
No locals.