Windows: Cannot create new files with Append mode

[franzpoeschel]

Describe the bug On Linux, the Append mode can be used to create new files. On Windows, the program aborts if the file does not yet exist.

To Reproduce

#include <adios2.h>

int main()
{
    adios2::ADIOS adios;
    auto IO = adios.DeclareIO("adsf");
    auto engine = IO.Open("asdf.bp", adios2::Mode::Append);
}

cmake_minimum_required(VERSION 3.12.0)

project(adios_testing)
find_package(ADIOS2 REQUIRED)

add_executable(adios2_append adios2_append.cpp)
target_link_libraries(adios2_append PRIVATE adios2::cxx11)

Expected behavior Creating a file with Append mode should consistently work on all supported platforms. This is useful e.g. for simulation codes, e.g. setting Append mode by default, so that restarting from a checkpoint will not delete previous data, but append to the data.

Desktop (please complete the following information):

• OS/Platform: Windows 10
• Build: ADIOS2 v2.8.3, Visual Studio 2019 Compiler, Debug build

Additional context Add any other context about the problem here.

Following up Was the issue fixed? Please report back.

[franzpoeschel]

Catching and printing the error:

[ADIOS2 EXCEPTION] <Toolkit> <transport::file::FileFStream> <CheckFile> : coudn't open file asdf.bp\data.0, check permissions or path existence, in call to fstream open : iostream stream error

@pnorbert suggested adding IO.AddTransport("file", {{"Library", "stdio"}});, this results in another error ("Invalid file open mode", 0).

As we have a workaround for this in our implementation, this is not really critical.