Differential fails under PHP 8.1 with error
AH01071: Got error 'PHP message: [2023-06-30 07:26:06] EXCEPTION: (RuntimeException) strlen(): Passing null to parameter #1 ($string) of type string is deprecated at [<arcanist>/src/error/PhutilErrorHandler.php:261]PHP message: arcanist(head=master, ref.master=8130241a11ac, custom=4), phorge(head=master, ref.master=7c1487e4dcfa)PHP message: #0 <#2> PhutilErrorHandler::handleError(integer, string, string, integer) called at [<phorge>/src/applications/differential/storage/DifferentialChangeset.php:328]PHP message: #1 <#2> DifferentialChangeset::getOldStatePathVector() called at [<phorge>/src/infrastructure/diff/view/PHUIDiffTableOfContentsListView.php:76]PHP message: #2 <#2> javelin_tag(string, array, PHUITabView) called at [<phorge>/src/view/phui/PHUITabGroupView.php:120]PHP message: #3 <#2> phutil_tag(string, array, array) called at [<phorge>/src/infrastructure/javelin/markup.php:70]PHP message: #4 <#2> phutil_tag(string, array, array) called at [<phorge>/src/view/phui/PHUITwoColumnView.php:242]PHP message: #5 <#2> PHUITwoColumnView::buildFooter() called at [<phorge>/src/view/phui/PHUITwoColumnView.php:123]PHP message: #6 <#2> PHUITwoColumnView::getTagContent() called at [<phorge>/src/view/AphrontTagView.php:161]PHP message: #7 <#2> phutil_tag(string, array, array) called at [<phorge>/src/view/formation/PHUIFormationContentView.php:18]PHP message: #8 <#2> phutil_escape_html(PHUIFormationContentView) called at [<phorge>/src/infrastructure/markup/render.php:139]PHP message: #9 <#2> phutil_escape_html(array) called at [<phorge>/src/infrastructure/markup/render.php:97]PHP message: #10 <#2> phutil_tag(string, array, array) called at [<phorge>/src/view/formation/PHUIFormationView.php:67]PHP message: #11 <#2> PHUIFormationView::render() called at [<phorge>/src/view/AphrontView.php:222]PHP message: #12 <#2> AphrontView::producePhutilSafeHTML() called at [<phorge>/src/infrastructure/markup/render.php:115]PHP message: #13 <#2> phutil_escape_html(PHUIFormationView) called at [<phorge>/src/infrastructure/markup/render.php:171]PHP message: #14 <#2> phutil_implode_html(string, array) called at [<phorge>/src/view/page/PhabricatorBarePageView.php:58]PHP message: #15 <#2> PhabricatorBarePageView::willRenderPage() called at [<phorge>/src/view/page/PhabricatorStandardPageView.php:216]PHP message: #16 <#2> PhabricatorStandardPageView::willRenderPage() called at [<phorge>/src/view/page/AphrontPageView.php:46]PHP message: #17 <#2> AphrontPageView::render() called at [<phorge>/src/view/page/PhabricatorStandardPageView.php:904]PHP message: #18 <#2> PhabricatorStandardPageView::produceAphrontResponse() called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:722]PHP message: #19 <#2> AphrontApplicationConfiguration::produceResponse(AphrontRequest, PhabricatorStandardPageView) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:299]PHP message: #20 phlog(RuntimeException) called at [<phorge>/src/aphront/handler/PhabricatorDefaultRequestExceptionHandler.php:41]PHP message: #21 PhabricatorDefaultRequestExceptionHandler::handleRequestThrowable(AphrontRequest, RuntimeException) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:751]PHP message: #22 AphrontApplicationConfiguration::handleThrowable(RuntimeException) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:337]PHP message: #23 AphrontApplicationConfiguration::processRequest(AphrontRequest, PhutilDeferredLog, AphrontPHPHTTPSink, MultimeterControl) called at [<phorge>/src/aphront/configuration/AphrontApplicationConfiguration.php:204]PHP message: #24 AphrontApplicationConfiguration::runHTTPRequest(AphrontPHPHTTPSink) called at [<phorge>/webroot/index.php:35]'