The issue from yesterday was closed (#30601 (comment)), so opening a new issue for this, because the workaround does not fix the issue.

The error is:

test/system_tests.cpp(88): error: in "system_tests/run_command": check what.find(expected) != std::string::npos has failed 

As a temporary workaround, one can try --disable-external-signer, if they don't need it. Alternatively, they can set a different locale, for just the tests.

A fix would be something like #28286, if someone wants to pick that up.