Crashing in trimming QPixmapCache

#0  0x00007ffff6adfa4b in QCache<QPixmapCache::Key, QPixmapCacheEntry>::Value::~Value (this=0x55555ad41760, __in_chrg=<optimized out>)
    at qtbase/include/QtCore/../../../../qtbase/src/corelib/tools/qcache.h:71
#1  QCache<QPixmapCache::Key, QPixmapCacheEntry>::Node::~Node (this=0x55555ad41748, __in_chrg=<optimized out>)
    at qtbase/include/QtCore/../../../../qtbase/src/corelib/tools/qcache.h:84
#2  QHashPrivate::Span<QCache<QPixmapCache::Key, QPixmapCacheEntry>::Node>::erase (bucket=16, this=<optimized out>)
    at qtbase/include/QtCore/../../../../qtbase/src/corelib/tools/qhash.h:352
#3  QHashPrivate::Data<QCache<QPixmapCache::Key, QPixmapCacheEntry>::Node>::erase (it=..., 
    this=0x7ffff71bd7e0 <(anonymous namespace)::Q_QGS_pm_cache::innerFunction()::holder+32>)
    at qtbase/include/QtCore/../../../../qtbase/src/corelib/tools/qhash.h:650
#4  QCache<QPixmapCache::Key, QPixmapCacheEntry>::unlink (this=0x7ffff71bd7d0 <(anonymous namespace)::Q_QGS_pm_cache::innerFunction()::holder+16>,
    n=<optimized out>) at qtbase/include/QtCore/../../../../qtbase/src/corelib/tools/qcache.h:159
#5  0x00007ffff6adac61 in QCache<QPixmapCache::Key, QPixmapCacheEntry>::trim (m=1886,
    this=0x7ffff71bd7d0 <(anonymous namespace)::Q_QGS_pm_cache::innerFunction()::holder+16>)
    at qtbase/include/QtCore/../../../../qtbase/src/corelib/tools/qcache.h:186
#6  QCache<QPixmapCache::Key, QPixmapCacheEntry>::setMaxCost (m=1886,
    this=0x7ffff71bd7d0 <(anonymous namespace)::Q_QGS_pm_cache::innerFunction()::holder+16>)
    at qtbase/include/QtCore/../../../../qtbase/src/corelib/tools/qcache.h:210
#7  QPMCache::flushDetachedPixmaps (this=0x7ffff71bd7c0 <(anonymous namespace)::Q_QGS_pm_cache::innerFunction()::holder>, nt=<optimized out>)
    at ../qtbase/src/gui/image/qpixmapcache.cpp:293
#8  0x00007ffff6adb99d in QPMCache::timerEvent (this=0x7ffff71bd7c0 <(anonymous namespace)::Q_QGS_pm_cache::innerFunction()::holder>)
    at ../qtbase/src/gui/image/qpixmapcache.cpp:316
#9  0x00007ffff632d75f in QObject::event (this=0x7ffff71bd7c0 <(anonymous namespace)::Q_QGS_pm_cache::innerFunction()::holder>, e=0x7fffffffd0f0)
    at ../qtbase/src/corelib/kernel/qobject.cpp:1387
#10 0x00007ffff734cf96 in QApplicationPrivate::notify_helper (this=<optimized out>,
    receiver=0x7ffff71bd7c0 <(anonymous namespace)::Q_QGS_pm_cache::innerFunction()::holder>, e=0x7fffffffd0f0)
    at ../qtbase/src/widgets/kernel/qapplication.cpp:3409
#11 0x00007ffff62dcbba in QCoreApplication::notifyInternal2 (receiver=0x7ffff71bd7c0 <(anonymous namespace)::Q_QGS_pm_cache::innerFunction()::holder>,
    event=0x7fffffffd0f0) at ../qtbase/src/corelib/kernel/qcoreapplication.cpp:1063
#12 0x00007ffff6471d8b in QTimerInfoList::activateTimers (this=0x555555622310) at ../qtbase/src/corelib/kernel/qtimerinfo_unix.cpp:639
#13 0x00007ffff6555594 in timerSourceDispatch (source=<optimized out>) at ../qtbase/src/corelib/kernel/qeventdispatcher_glib.cpp:185
#14 idleTimerSourceDispatch (source=<optimized out>) at ../qtbase/src/corelib/kernel/qeventdispatcher_glib.cpp:232
#15 0x00007ffff515c8eb in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#16 0x00007ffff51afd28 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#17 0x00007ffff515a023 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#18 0x00007ffff65558ee in QEventDispatcherGlib::processEvents (this=0x555555629ee0, flags=...)
--Type <RET> for more, q to quit, c to continue without paging--
    at ../qtbase/src/corelib/kernel/qeventdispatcher_glib.cpp:429
#19 0x00007ffff62e9713 in QEventLoop::exec (this=this@entry=0x7fffffffd340, flags=..., flags@entry=...)
    at qtbase/include/QtCore/../../../../qtbase/src/corelib/global/qflags.h:69
#20 0x00007ffff62e5323 in QCoreApplication::exec () at qtbase/include/QtCore/../../../../qtbase/src/corelib/global/qflags.h:109
#21 0x0000555555563008 in main ()
(gdb) print t
$1 = (QPixmapCacheEntry *) 0x404040404040404