File.Exists causes app to fail when file not found and used in a Class.

[richardschoen]

Was working on a sample app and getting this error from a System.IO.File.Exists check if a file is not found if I use within a class. If file is found, no error. Weird.

Kills the .Net app completely.

Only happens on latest mono code. (1/19/19 snapshot).

Looks to be threading related perhaps.

I simply reverted to the 10/14/18 snapshot and all works fine again.

Appears to be something that broke between releases.

Stacktrace:

at <0xffffffff>
at System.Threading.Tasks.Task.ExecuteWithThreadLocal (System.Threading.T
at System.Threading.Tasks.Task.ExecuteEntry (bool) [0x0005e] in <a945e967
at System.Threading.Tasks.Task.System.Threading.IThreadPoolWorkItem.Execu
at System.Threading.ThreadPoolWorkQueue.Dispatch () [0x00096] in <a945e96
at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback () [0x000
at (wrapper runtime-invoke) .runtime_invoke_bool (object,intptr,i
Memory around native instruction pointer (900000002984b48):
900000002984b38 60 00 00 00 eb ff 00 10 2f bf 00 00 41 9e 00 88 ......./ at System.Threading.Tasks.Task.ExecuteEntry (bool) [0x0005e] in <a945e967 at System.Threading.Tasks.Task.System.Threading.IThreadPoolWorkItem.Execu at System.Threading.ThreadPoolWorkQueue.Dispatch () [0x00096] in <a945e96 at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback () [0x000 at (wrapper runtime-invoke) <Module>.runtime_invoke_bool (object,intptr,i mory around native instruction pointer (900000002984b48): 0000002984b38 60 00 00 00 eb ff 00 10 2f bf 00 00 41 9e 00 88 ......./
0000002984b48 e8 7f 00 00 f8 41 00 28 7f 84 e3 78 e9 3d 00 00 .....A.(.
0000002984b58 e9 7d 00 10 7d 29 03 a6 e8 5d 00 08 4e 80 04 21 .}..})...
0000002984b68 e8 41 00 28 2f a3 00 00 41 9e ff cc 2f ba 00 00 .A.(/...A

[NattyNarwhal]

Do you have an example program to run this against? I wouldn't be surprised if this is more CoreFX fallout.