<?xml version="1.0" encoding="UTF-8"?>
<phpunit
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
    backupGlobals="false"
    backupStaticAttributes="false"
    bootstrap="vendor/autoload.php"
    colors="true"
    convertErrorsToExceptions="true"
    convertNoticesToExceptions="true"
    convertWarningsToExceptions="true"
    processIsolation="false"
    stopOnFailure="false"
>
    <filter>
        <whitelist>
            <directory>./</directory>
        </whitelist>
    </filter>
    <testsuites>
        <testsuite name="Tree test suite">
            <directory>./tests/</directory>
        </testsuite>
    </testsuites>
</phpunit>

<?xml version="1.0" encoding="UTF-8"?>
<phpunit
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
    backupGlobals="false"
    backupStaticAttributes="false"
    bootstrap="vendor/autoload.php"
    cacheResultFile=".build/phpunit/unit.cache"
    colors="true"
    convertErrorsToExceptions="true"
    convertNoticesToExceptions="true"
    convertWarningsToExceptions="true"
    processIsolation="false"
    stopOnFailure="false"
>
    <filter>
        <whitelist>
            <directory>./</directory>
        </whitelist>
    </filter>
    <testsuites>
        <testsuite name="Tree test suite">
            <directory>./tests/</directory>
        </testsuite>
    </testsuites>
</phpunit>

Configure cache result file location
Fix: Configure cache result file location
