基于此文档 - https://developer.android.com/studio/test/command-line.html#AMOptionsSyntax 可以从Firebase实验室获取代码覆盖率结果。在firebase-community.slack.com的#test-lab中的一些人能够使它工作，但经过几次尝试后我仍然撞墙。
我可以通过以下方式获得jacaco和emma的组合覆盖率报告 本指南 所以我的本地设置没有任何问题，但在尝试为gcloud cmd行提供参数以询问覆盖数时会出现问题，并且它会讨论艾玛的覆盖范围。
基本上，当我在本地运行此命令时
gcloud beta test android run \
--type instrumentation \
--app app/build/outputs/apk/*-debug-unaligned.apk \
--test app/build/outputs/apk/*-debug-androidTest-unaligned.apk \
--device-ids Nexus6\
--os-version-ids 22 \
--locales en \
--orientations portrait \
--environment-variables coverage=true,coverageFile="/sdcard/coverage.ec" \
--directories-to-pull=/sdcard
我期待生成覆盖率报告，但我在instruments.results文件中得到了这个
INSTRUMENTATION_STATUS: numtests=1
INSTRUMENTATION_STATUS: stream=
com.godaddy.gdm.telephony.uitests.DialerTabTest:
INSTRUMENTATION_STATUS: id=AndroidJUnitRunner
INSTRUMENTATION_STATUS: test=dialerTabNumberFormattingTest
INSTRUMENTATION_STATUS: current=1
INSTRUMENTATION_STATUS_CODE: 1
INSTRUMENTATION_STATUS: numtests=1
INSTRUMENTATION_STATUS: stream=.
INSTRUMENTATION_STATUS: id=AndroidJUnitRunner
INSTRUMENTATION_STATUS: test=dialerTabNumberFormattingTest
INSTRUMENTATION_STATUS: current=1
INSTRUMENTATION_STATUS_CODE: 0
INSTRUMENTATION_RESULT: stream=
Time: 6.022
OK (1 test)
Error: **Failed to generate emma coverage.**
INSTRUMENTATION_CODE: -1
而logcat说：
11-18 21:38:39.400: I/TestRunner(5246): run finished: 1 tests, 0 failed, 0 ignored
11-18 21:38:39.400: I/TestRunner(5246): [ 11-18 21:38:39.400 5246: 5263 E/ ]
11-18 21:38:39.400: I/TestRunner(5246): Failed to generate emma coverage.
11-18 21:38:39.400: I/TestRunner(5246): java.lang.reflect.InvocationTargetException
11-18 21:38:39.400: I/TestRunner(5246): at java.lang.reflect.Method.invoke(Native Method)
11-18 21:38:39.400: I/TestRunner(5246): at java.lang.reflect.Method.invoke(Method.java:372)
11-18 21:38:39.400: I/TestRunner(5246): at android.support.test.internal.runner.listener.CoverageListener.generateCoverageReport(CoverageListener.java:80)
11-18 21:38:39.400: I/TestRunner(5246): at android.support.test.internal.runner.listener.CoverageListener.instrumentationRunFinished(CoverageListener.java:68)
11-18 21:38:39.400: I/TestRunner(5246): at android.support.test.internal.runner.TestExecutor.reportRunEnded(TestExecutor.java:94)
11-18 21:38:39.400: I/TestRunner(5246): at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:69)
11-18 21:38:39.400: I/TestRunner(5246): at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:262)
11-18 21:38:39.400: I/TestRunner(5246): at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1853)
11-18 21:38:39.400: I/TestRunner(5246): Caused by: java.io.FileNotFoundException: /sdcard/coverage.ec: open failed: EACCES (Permission denied)
11-18 21:38:39.400: I/TestRunner(5246): at libcore.io.IoBridge.open(IoBridge.java:456)
11-18 21:38:39.400: I/TestRunner(5246): at java.io.FileOutputStream.<init>(FileOutputStream.java:87)
11-18 21:38:39.400: I/TestRunner(5246): at com.vladium.emma.rt.RT.dumpCoverageData(RT.java:50)
11-18 21:38:39.400: I/TestRunner(5246): ... 8 more
11-18 21:38:39.400: I/TestRunner(5246): Caused by: android.system.ErrnoException: open failed: EACCES (Permission denied)
11-18 21:38:39.400: I/TestRunner(5246): at libcore.io.Posix.open(Native Method)
11-18 21:38:39.400: I/TestRunner(5246): at libcore.io.BlockGuardOs.open(BlockGuardOs.java:186)
11-18 21:38:39.400: I/TestRunner(5246): at libcore.io.IoBridge.open(IoBridge.java:442)
11-18 21:38:39.400: I/TestRunner(5246): ... 10 more
如果需要，我可以提供更多信息。