Thread 2 (Thread 0x7f20dfbce710 (LWP 9383)):
#0  0x00007f210cbf738d in read () from /lib64/libpthread.so.0
#1  0x000000000048d34e in mono_handle_native_sigsegv (
    signal=<value optimized out>, ctx=<value optimized out>)
    at mini-exceptions.c:1999
#2  0x00000000004dc4ef in mono_arch_handle_altstack_exception (sigctx=
    0x7f20df9cdc40, fault_addr=<value optimized out>, stack_ovf=0)
    at exceptions-amd64.c:924
#3  <signal handler called>
#4  0x00000000004b0e0e in process_breakpoint_inner () at debugger-agent.c:3563
#5  process_breakpoint () at debugger-agent.c:3636
#6  0x00007f20dfbcce60 in ?? ()
#7  0x00007f210d4e9d48 in ?? ()
#8  0x00007f20e40f0888 in ?? ()
#9  0x00007f20e40f0888 in ?? ()
#10 0x00007f20e7348120 in ?? ()
#11 0x00007f20e74f1aa0 in ?? ()
#12 0x0000000000000000 in ?? ()