Current master, Ubuntu:

Repeatedly running `validation_block_tests/processnewblock_signals_ordering`, a test that creates multiple threads to test the validation interface, sporadically writes weird messages to stdout (with the test passing).
Running 
`for i in {1..30}; do ./src/test/test_bitcoin --run_test=validation_block_tests/processnewblock_signals_ordering; done` 
usually gives me multiple occurrences of this.

It  sometimes writes code fragments such as "pindexNew->GetBlockHash()", "m_expected_tip", "==", in other runs single log entries.

Can someone reproduce this? 
Obviously this is just a small nuisance in itself, still reporting this in case the root cause might be interesting.
/**
 * See https://www.boost.org/doc/libs/1_71_0/libs/test/doc/html/boost_test/utf_reference/link_references/link_boost_test_module_macro.html
 */
#define BOOST_TEST_MODULE Bitcoin Core Test Suite
#include <boost/test/unit_test.hpp>
#include <test/util/setup_common.h>
const std::function<void(const std::string&)> G_TEST_LOG_FUN = [](const std::string& s) {
    if (s.back() == '\n') {
        
        BOOST_TEST_MESSAGE(s.substr(0, s.size() - 1));
    } else {
        BOOST_TEST_MESSAGE(s);
    }
};