Android manifest merger error messages are unnecessarily dropped

[jin]

Repro: compile an Android project with the following invalid manifest:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.bazel"
    android:versionCode="1"
    android:versionName="1.0" />

  <uses-sdk
      android:minSdkVersion="21"
      android:targetSdkVersion="26" />

</manifest>

Note the incorrect /> in the opening <manifest> element.

Bazel crashes with:

INFO: Found 1 target...
ERROR: /usr/local/google/home/jingwen/code/examples/android/tutorial-test/src/main/BUILD:1:1: Merging manifest for //src/main:greeter_app failed (Exit 1) ResourceProcessorBusyBox failed: error executing command bazel-out/host/bin/external/bazel_tools/src/tools/android/java/com/google/devtools/build/android/ResourceProcessorBusyBox --tool MERGE_MANIFEST -- --manifest src/main/AndroidManifest.xml ... (remaining 8 argument(s) skipped)

Use --sandbox_debug to see verbose messages from the sandbox
Target //src/main:greeter_app failed to build
Use --verbose_failures to see the command lines of failed build steps.
INFO: Elapsed time: 9.480s, Critical Path: 3.73s
INFO: 9 processes: 8 linux-sandbox, 1 worker.
FAILED: Build did NOT complete successfully

It is expected to crash with:

ERROR: /usr/local/google/home/jingwen/code/examples/android/tutorial-test/src/main/BUILD:1:1: Merging manifest for //src/main:greeter_app failed (Exit 1) ResourceProcessorBusyBox failed: error executing command bazel-out/host/bin/external/bazel_tools/src/tools/android/java/com/google/devtools/build/android/ResourceProcessorBusyBox --tool MERGE_MANIFEST -- --manifest src/main/AndroidManifest.xml ... (remaining 8 argument(s) skipped)

Use --sandbox_debug to see verbose messages from the sandbox
Dec 12, 2018 1:23:25 PM com.google.devtools.build.android.ManifestMergerAction main
SEVERE: Encountered error while attempting to merge manifests
com.google.devtools.build.android.AndroidManifestProcessor$ManifestProcessingException: com.android.manifmerger.ManifestMerger2$MergeFailureException: org.xml.sax.SAXParseException; lineNumber: 7; columnNumber: 4; The markup in the document following the root element must be well-formed.
	at com.google.devtools.build.android.AndroidManifestProcessor.mergeManifest(AndroidManifestProcessor.java:189)
	at com.google.devtools.build.android.ManifestMergerAction.main(ManifestMergerAction.java:215)
	at com.google.devtools.build.android.ResourceProcessorBusyBox$Tool$11.call(ResourceProcessorBusyBox.java:126)
	at com.google.devtools.build.android.ResourceProcessorBusyBox.processRequest(ResourceProcessorBusyBox.java:240)
	at com.google.devtools.build.android.ResourceProcessorBusyBox.main(ResourceProcessorBusyBox.java:203)
Caused by: com.android.manifmerger.ManifestMerger2$MergeFailureException: org.xml.sax.SAXParseException; lineNumber: 7; columnNumber: 4; The markup in the document following the root element must be well-formed.
	at com.android.manifmerger.ManifestMerger2.load(ManifestMerger2.java:474)
	at com.android.manifmerger.ManifestMerger2.merge(ManifestMerger2.java:130)
	at com.android.manifmerger.ManifestMerger2.access$1100(ManifestMerger2.java:58)
	at com.android.manifmerger.ManifestMerger2$Invoker.merge(ManifestMerger2.java:1163)
	at com.google.devtools.build.android.AndroidManifestProcessor.mergeManifest(AndroidManifestProcessor.java:163)
	... 4 more
Caused by: org.xml.sax.SAXParseException; lineNumber: 7; columnNumber: 4; The markup in the document following the root element must be well-formed.
	at java.xml/com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.fatalError(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLScanner.reportFatalError(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$TrailingMiscDriver.next(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
	at java.xml/com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(Unknown Source)
	at com.android.utils.PositionXmlParser.parse(PositionXmlParser.java:181)
	at com.android.utils.PositionXmlParser.parse(PositionXmlParser.java:139)
	at com.android.utils.PositionXmlParser.parse(PositionXmlParser.java:101)
	at com.android.utils.PositionXmlParser.parse(PositionXmlParser.java:110)
	at com.android.manifmerger.XmlLoader.load(XmlLoader.java:63)
	at com.android.manifmerger.ManifestMerger2.load(ManifestMerger2.java:466)
	... 8 more

Target //src/main:greeter_app failed to build
Use --verbose_failures to see the command lines of failed build steps.
INFO: Elapsed time: 10.157s, Critical Path: 3.57s
INFO: 9 processes: 8 linux-sandbox, 1 worker.
FAILED: Build did NOT complete successfully