ttrss/vendor/open-telemetry/sdk/Common/Dev/Compatibility/README.md

Backwards Compatibility

We aim to provide backward compatibility (without any guarantee) even for alpha releases, however the library will raise notices indicating breaking changes and what to do about them.
If you don't want these notices to appear or change the error message level, you can do so by calling:

OpenTelemetry\SDK\Common\Dev\Compatibility\Util::setErrorLevel(0)

to turn messages off completely, or (for example)

OpenTelemetry\SDK\Common\Dev\Compatibility\Util::setErrorLevel(E_USER_DEPRECATED)

to trigger only deprecation notices. Valid error levels are 0 (none), E_USER_DEPRECATED, E_USER_NOTICE, E_USER_WARNING and E_USER_ERROR
However (as long as in alpha) it is safer to pin a dependency on the library to a specific version and/or make the adjustments mentioned in the provided messages, since doing otherwise may break things completely for you in the future!