Estou usando a versão mais nova (04/2019 do Rstudio no Ubuntu 18.04 (64 bits), tenho dois PC, um desktop e um laptop, o laptop nunca teve esse problema, porém o desktop trava constantemente sem nenhum sinal, pode acontecer quando não estou fazendo nada, ou seleciono algo, ou carrego um pacote, etc.
Então, o que poderia dar errado?
PS: algo com certeza trava: clique com o botão direito no terminal e selecione "inspecionar elemento". Alguns logs quando ele trava no terminal:
nouveau: kernel rejected pushbuf: No such file or directory
nouveau: ch16: krec 0 pushes 0 bufs 2 relocs 0
nouveau: ch16: buf 00000000 00000002 00000004 00000004 00000000
nouveau: ch16: buf 00000001 00000006 00000004 00000000 00000004
Received signal 11 SEGV_MAPERR 000000000143
#0 0x7f6d99a4ca4f
#1 0x7f6d99a4ce4b
#2 0x7f6d99a4d4ce
#3 0x7f6d94cb5890
#4 0x7f6d6e8af1f9
#5 0x7f6d6e8bfd5f
#6 0x7f6d6e8c49e4
#7 0x7f6d6e478629
#8 0x7f6d96cfe876 QSGBatchRenderer::Renderer::renderBatches()
#9 0x7f6d96d03ef3 QSGBatchRenderer::Renderer::render()
#10 0x7f6d96cf4a23 QSGRenderer::renderScene()
#11 0x7f6d96cf4f07 QSGRenderer::renderScene()
#12 0x7f6d96d31c7e QSGDefaultRenderContext::renderNextFrame()
#13 0x7f6d96d8d1d4 QQuickWindowPrivate::renderSceneGraph()
#14 0x7f6d96e48118 QQuickRenderControl::render()
#15 0x7f6d92706d50 QQuickWidgetPrivate::render()
#16 0x7f6d92706f9e QQuickWidgetPrivate::renderSceneGraph()
#17 0x7f6d951617bb QObject::event()
#18 0x7f6d960abfd3 QWidget::event()
#19 0x7f6d9270aacb QQuickWidget::event()
#20 0x7f6d9f136c88 QtWebEngineCore::RenderWidgetHostViewQtDelegateWidget::event()
#21 0x7f6d9606db3c QApplicationPrivate::notify_helper()
#22 0x7f6d96074d30 QApplication::notify()
#23 0x7f6d95134e28 QCoreApplication::notifyInternal2()
#24 0x7f6d9518b6a9 QTimerInfoList::activateTimers()
#25 0x7f6d9518be81 timerSourceDispatch()
#26 0x7f6d8c4b1317 g_main_context_dispatch
#27 0x7f6d8c4b1550
#28 0x7f6d8c4b15dc g_main_context_iteration
#29 0x7f6d9518c1ef QEventDispatcherGlib::processEvents()
#30 0x7f6d9513378a QEventLoop::exec()
#31 0x7f6d9513c190 QCoreApplication::exec()
#32 0x55822dfa284f main
#33 0x7f6d9300eb97 __libc_start_main
#34 0x55822dfa5b8a _start
r8: 0000000000000014 r9: 0000000000000048 r10: 000055822e993a80 r11: 0000000000000004
r12: 000055822ec952f8 r13: 00007f6d2c10f8c0 r14: 0000000000000200 r15: 000055822e982800
di: 00007f6d2c10f8c0 si: 000055822ec952e8 bp: 000055822ec952e8 bx: 00000000000000fb
dx: 0000000000000001 ax: 0000000000000200 cx: 000055822e993b60 sp: 00007ffe377b0f70
ip: 00007f6d6e8af1f9 efl: 0000000000010202 cgf: 002b000000000033 erf: 0000000000000004
trp: 000000000000000e msk: 0000000000000000 cr2: 0000000000000143
[end of stack trace]
Calling _exit(1). Core file will not be generated.
Eu descobri depois de ver muitos posts. O desktop que utilizo possui placa gráfica Nvdia GTX 1070 e o driver anterior era servidor X.Org X, onde acho que houve algum problema de compatibilidade, após atualizar para driver Nvdia conforme descrito aqui , tudo resolvido.