Hi,
I compiled project with -strict and almost same errors logged (I think GWT compiler does not merge 2 super-source packages like 'java.util' and 'java.beans'). Here is the stacktrace:
[java] Compiling module com.test.sample.Sample
[java] Tracing compile failure path for type 'com.google.gwt.cell.client.EditTextCell'
[java] [ERROR] Errors in 'com/google/gwt/cell/client/EditTextCell.java'
[java] [ERROR] Line 336: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.dom.builder.client.DomStylesBuilder'
[java] [ERROR] Errors in 'com/google/gwt/dom/builder/client/DomStylesBuilder.java'
[java] [ERROR] Line 113: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.dom.client.DataTransfer'
[java] [ERROR] Errors in 'com/google/gwt/dom/client/DataTransfer.java'
[java] [ERROR] Line 127: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.user.cellview.client.AbstractCellTable'
[java] [ERROR] Errors in 'com/google/gwt/user/cellview/client/AbstractCellTable.java'
[java] [ERROR] Line 744: ROOT cannot be resolved or is not a field
[java] [ERROR] Line 477: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.user.client.ui.MultiWordSuggestOracle'
[java] [ERROR] Errors in 'com/google/gwt/user/client/ui/MultiWordSuggestOracle.java'
[java] [ERROR] Line 534: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.dom.client.HeadingElement'
[java] [ERROR] Errors in 'com/google/gwt/dom/client/HeadingElement.java'
[java] [ERROR] Line 91: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.user.client.ui.AbsolutePanel'
[java] [ERROR] Errors in 'com/google/gwt/user/client/ui/AbsolutePanel.java'
[java] [ERROR] Line 280: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.user.client.ui.UIObject'
[java] [ERROR] Errors in 'com/google/gwt/user/client/ui/UIObject.java'
[java] [ERROR] Line 657: ROOT cannot be resolved or is not a field
[java] [ERROR] Line 775: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.safehtml.shared.UriUtils'
[java] [ERROR] Errors in 'com/google/gwt/safehtml/shared/UriUtils.java'
[java] [ERROR] Line 240: ROOT cannot be resolved or is not a field
[java] [ERROR] Line 235: ROOT cannot be resolved or is not a field
[java] [ERROR] Line 84: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.user.cellview.client.CellBasedWidgetImplTrident'
[java] [ERROR] Errors in 'com/google/gwt/user/cellview/client/CellBasedWidgetImplTrident.java'
[java] [ERROR] Line 253: ROOT cannot be resolved or is not a field
[java] [ERROR] Line 191: ROOT cannot be resolved or is not a field
[java] [ERROR] Line 157: ROOT cannot be resolved or is not a field
[java] [ERROR] Line 245: ROOT cannot be resolved or is not a field
[java] [ERROR] Errors in 'com/google/gwt/user/cellview/client/CellBasedWidgetImpl.java'
[java] [ERROR] Line 74: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.user.cellview.client.CellBasedWidgetImpl'
[java] [ERROR] Errors in 'com/google/gwt/user/cellview/client/CellBasedWidgetImpl.java'
[java] [ERROR] Line 74: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.dom.builder.shared.HtmlStylesBuilder'
[java] [ERROR] Errors in 'com/google/gwt/dom/builder/shared/HtmlStylesBuilder.java'
[java] [ERROR] Line 111: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.view.client.DefaultSelectionEventManager'
[java] [ERROR] Errors in 'com/google/gwt/view/client/DefaultSelectionEventManager.java'
[java] [ERROR] Line 154: ROOT cannot be resolved or is not a field
[java] [ERROR] Line 156: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'com.google.gwt.i18n.shared.DateTimeFormat'
[java] [ERROR] Errors in 'com/google/gwt/i18n/shared/DateTimeFormat.java'
[java] [ERROR] Line 1399: ROOT cannot be resolved or is not a field
[java] [ERROR] Line 1405: ROOT cannot be resolved or is not a field
[java] Tracing compile failure path for type 'java.util.logging.Level'
[java] [ERROR] Errors in 'com/google/gwt/emul/java/util/logging/Level.java'
[java] [ERROR] Line 90: ROOT cannot be resolved or is not a field
[java] Finding entry point classes
[java] Tracing compile failure path for type 'com.google.gwt.logging.client.LogConfiguration'
[java] [ERROR] Errors in 'com/google/gwt/logging/client/LogConfiguration.java'
[java] [ERROR] java.util.logging.Level cannot be resolved to a type
[java] [ERROR] Errors in 'com/google/gwt/emul/java/util/logging/Handler.java'
[java] [ERROR] java.util.logging.Level cannot be resolved to a type
[java] [ERROR] Errors in 'com/google/gwt/emul/java/util/logging/Logger.java'
[java] [ERROR] java.util.logging.Level cannot be resolved to a type
[java] [ERROR] Errors in 'com/google/gwt/emul/java/util/logging/Level.java'
[java] [ERROR] Line 90: ROOT cannot be resolved or is not a field
[java] [ERROR] Errors in 'com/google/gwt/emul/java/util/logging/LogRecord.java'
[java] [ERROR] java.util.logging.Level cannot be resolved to a type
[java] [ERROR] Errors in 'com/google/gwt/emul/java/util/logging/Formatter.java'
[java] [ERROR] java.util.logging.LogRecord cannot be resolved to a type
[java] Tracing compile failure path for type 'com.test.sample.client.SampleEntryPoint'
[java] [ERROR] Errors in 'file:/C:/Users/user/AppData/Local/Temp/sample/gwt-classpath/com/test/sample/client/SampleEntryPoint.java'
[java] [ERROR] com.test.core.client.service.DefaultAsyncCallback cannot be resolved to a type
[java] [ERROR] Errors in 'file:/C:/Users/user/AppData/Local/Temp/sample/gwt-classpath/com/test/core/client/entrypoint/BaseEntryPoint.java'
[java] [ERROR] com.google.gwt.user.client.ui.Widget cannot be resolved to a type
[java] [ERROR] Errors in 'file:/C:/Users/user/AppData/Local/Temp/sample/gwt-classpath/com/test/core/client/service/DefaultAsyncCallback.java'
[java] [ERROR] com.google.gwt.user.client.ui.Widget cannot be resolved to a type