Current behavior:

Poco::ConsoleChannel uses std::clog by default, which implies output to stderr.
Poco::WindowsConsoleChannel writes (hardcoded) to stdout instead.

Correct behavior:

WindowsConsoleChannel should write to stderr by default as well, because this does not interfer with "regular" output to stdout.

Should be trivial to fix (just replacing 2 occurrences of STANDARD_OUTPUT_HANDLE by STANDARD_ERROR_HANDLE in WindowsConsoleChannel.cpp). Do you want a PR for that?

Cheers
-Fritz