at <unknown> <0xffffffff>
  at (wrapper managed-to-native) Mono.Unix.Native.Stdlib.free (intptr) <0xffffffff>
  at Mono.Unix.UnixMarshal.FreeHeap (intptr) <0x00013>
  at Mono.Unix.Catalog.Init (string,string) <0x00163>
  at Pinta.MainClass.Main (string[]) <0x00127>
  at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) <0xffffffff>

Native stacktrace:

        /usr/bin/mono() [0x80ea42e]
        /usr/bin/mono() [0x812e944]
        /usr/bin/mono() [0x806ae39]
        linux-gate.so.1(__kernel_rt_sigreturn+0) [0xb77cfcec]
        /usr/lib/libc.so.6(+0x71a20) [0xb5191a20]
        /usr/lib/libc.so.6(cfree+0x50) [0xb5194ee0]
        [0xb713c534]
        [0xb713c4e4]
        [0xb713a144]
        [0xb71350d0]
        [0xb71356cc]
        /usr/bin/mono() [0x806a9a3]

Debug info from gdb:

[New LWP 6604]
[New LWP 6605]
warning: File "/usr/bin/mono-sgen-gdb.py" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
To enable execution of this file add
        add-auto-load-safe-path /usr/bin/mono-sgen-gdb.py
line to your configuration file "/home/learner/.gdbinit".
To completely disable this security protection add
        set auto-load safe-path /
line to your configuration file "/home/learner/.gdbinit".
For more information about this security protection see the
"Auto-loading safe path" section in the GDB manual.  E.g., run from the shell:
        info "(gdb)Auto-loading safe path"
warning: File "/usr/bin/mono-sgen-gdb.py" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/i686/libthread_db.so.1".
0xb77cfcd5 in __kernel_vsyscall ()
  Id   Target Id         Frame
* 1    Thread 0xb755c700 (LWP 6603) "mono" 0xb77cfcd5 in __kernel_vsyscall ()
  2    Thread 0xb6bffb40 (LWP 6604) "mono" 0xb77cfcd5 in __kernel_vsyscall ()
  3    Thread 0xb5879b40 (LWP 6605) "Finalizer" 0xb77cfcd5 in __kernel_vsyscall ()

Thread 3 (Thread 0xb5879b40 (LWP 6605)):
#0  0xb77cfcd5 in __kernel_vsyscall ()
#1  0xb77388e2 in __libc_do_syscall () from /lib/i686/libpthread.so.0
#2  0xb77349cf in do_futex_wait.constprop () from /lib/i686/libpthread.so.0
#3  0xb7734ad7 in __new_sem_wait_slow.constprop.1 () from /lib/i686/libpthread.so.0
#4  0x082511e7 in mono_sem_wait ()
#5  0x081d7d13 in finalizer_thread ()
#6  0x081ba97f in start_wrapper ()
#7  0x08257698 in inner_start_thread ()
#8  0xb772d4a5 in start_thread () from /lib/i686/libpthread.so.0
#9  0xb765180e in clone () from /lib/i686/libc.so.6

Thread 2 (Thread 0xb6bffb40 (LWP 6604)):
#0  0xb77cfcd5 in __kernel_vsyscall ()
#1  0xb773260b in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/i686/libpthread.so.0
#2  0x0822bd6c in thread_func ()
#3  0xb772d4a5 in start_thread () from /lib/i686/libpthread.so.0
#4  0xb765180e in clone () from /lib/i686/libc.so.6

Thread 1 (Thread 0xb755c700 (LWP 6603)):
#0  0xb77cfcd5 in __kernel_vsyscall ()
#1  0xb7736c2b in waitpid () from /lib/i686/libpthread.so.0
#2  0x080ea4eb in mono_handle_native_sigsegv ()
#3  0x0812e944 in mono_arch_handle_altstack_exception ()
#4  0x0806ae39 in mono_sigsegv_signal_handler ()
#5  <signal handler called>
#6  0xb5191a20 in _int_free () from /usr/lib/libc.so.6
#7  0xb5194ee0 in free () from /usr/lib/libc.so.6
#8  0xb713c534 in ?? ()
#9  0xb713c4e4 in ?? ()
#10 0xb713a144 in ?? ()
#11 0xb71350d0 in ?? ()
#12 0xb71356cc in ?? ()
#13 0x0806a9a3 in mono_jit_runtime_invoke ()
#14 0x081dea81 in mono_runtime_invoke ()
#15 0x081e0c9e in mono_runtime_exec_main ()
#16 0x080c1ffd in mono_main ()
#17 0x080672b7 in main ()

=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.
=================================================================