This test sometimes fail with:

TEST: /app/webkit/WebKitBuild/WPE/Release/bin/TestWebKitAPI/WPE/TestWebProcessExtensions...
  /webkit/WebKitWebProcessExtension/dom-document-title:               PASS
GLib-GIO-DEBUG: Using cross-namespace EXTERNAL authentication (this will deadlock if server is GDBus < 2.73.3)
EGLDisplay Initialization failed: EGL_NOT_INITIALIZED
  /webkit/WebKitWebProcessExtension/document-loaded-signal:           PASS
  /webkit/WebKitWebProcessExtension/window-object-cleared:            PASS
  /webkit/WebKitWebProcessExtension/isolated-world:                   PASS
  /webkit/WebKitWebProcessExtension/form-controls-associated-signal:  PASS
  /webkit/WebKitWebProcessExtension/form-submission-steps:            PASS
  /webkit/WebKitWebProcessExtension/page-id:                          FAIL
ERROR:/app/webkit/Tools/TestWebKitAPI/Tests/WebKitGLib/TestWebProcessExtensions.cpp:410:void webViewPageIDChanged(WebKitWebView*, GParamSpec*, bool*): 'Test::s_dbusConnectionPageMap.get(webkit_web_view_get_page_id(webView))' should not be nullptr
  /webkit/WebKitWebProcessExtension/user-messages:                    PASS
GLib-GIO-DEBUG: Using cross-namespace EXTERNAL authentication (this will deadlock if server is GDBus < 2.73.3)
EGLDisplay Initialization failed: EGL_NOT_INITIALIZED
  /webkit/WebKitWebView/web-process-crashed:                          PASS
TEST: /app/webkit/WebKitBuild/WPE/Release/bin/TestWebKitAPI/WPE/TestMultiprocess...
  /webkit/WebKitWebContext/process-per-web-view:                      PASS
GLib-GIO-DEBUG: Using cross-namespace EXTERNAL authentication (this will deadlock if server is GDBus < 2.73.3)
EGLDisplay Initialization failed: EGL_NOT_INITIALIZED
  /webkit/WebKitWebView/multiprocess-create-ready-close:              PASS
TEST: /app/webkit/WebKitBuild/WPE/Release/bin/TestWebKitAPI/WPE/TestResources...
  /webkit/WebKitWebView/resources:                                    PASS
GLib-GIO-DEBUG: Using cross-namespace EXTERNAL authentication (this will deadlock if server is GDBus < 2.73.3)
EGLDisplay Initialization failed: EGL_NOT_INITIALIZED
  /webkit/WebKitWebView/history-cache:                                PASS
  /webkit/WebKitWebView/sync-request-on-max-conns:                    PASS
  /webkit/WebKitWebResource/loading:                                  PASS
  /webkit/WebKitWebResource/response:                                 PASS
  /webkit/WebKitWebResource/mime-type:                                PASS


[...]

Unexpected failures (1)
    /WPE/TestWebProcessExtensions
        /webkit/WebKitWebProcessExtension/page-id


Example: https://ews-build.webkit.org/#/builders/41/builds/2740/steps/26/logs/stdio

It happens randomly on the EWS queue mainly at: https://ews-build.webkit.org/#/builders/API-Tests-WPE-EWS