如何获取标准规则执行开始时间？

问题描述

有时，我们的平台构建卡住并超时，因此当VM被杀死时，我们将丢失所有构建日志。为了找到原因，我们想使用Build event protocol来查看开始执行但没有完成的规则​​（通常是渴望内存的测试）。

This graph中的

official docs表明TargetConfigured和TargetCompleted事件是规则开始和结束之间的唯一事件。

但是实际上bazel同时配置了所有目标，因此我们不能仅从TargetCompleted时间中减去TargetConfigured时间。

此外，两个事件都不包含任何时间戳。这是sample repo中的构建事件文件（已截断）：

    {"id":{"targetConfigured":{"label":"//:B"}},"children":[{"targetCompleted":{"label":"//:B","configuration":{"id":"f157fdcaf05e7672fa1bf535fbb2c3edb004ce9e9a7f6d84d9bf031454e2fb64"}}}],"configured":{"targetKind":"java_binary rule","tag":["__JAVA_RULES_MIGRATION_DO_NOT_USE_WILL_BREAK__"]}}
    {"id":{"targetConfigured":{"label":"//:main"}},"children":[{"targetCompleted":{"label":"//:main","configured":{"targetKind":"java_library rule","tag":["__JAVA_RULES_MIGRATION_DO_NOT_USE_WILL_BREAK__"]}}
    {"id":{"targetConfigured":{"label":"//:step1"}},"children":[{"targetCompleted":{"label":"//:step1","configured":{"targetKind":"genrule rule"}}
    {"id":{"progress":{"opaqueCount":2}},"children":[{"progress":{"opaqueCount":3}},{"namedSet":{"id":"0"}}],"progress":{"stderr":"\r\u001b[1A\u001b[K\u001b[32mAnalyzing:\u001b[0m 3 targets (0 packages loaded,0 targets configured)\n\r\u001b[1A\u001b[K\u001b[32mINFO: \u001b[0mAnalyzed 3 targets (0 packages loaded,0 targets configured).\n\n\r\u001b[1A\u001b[K\u001b[32mINFO: \u001b[0mFound 3 targets...\n\n\r\u001b[1A\u001b[K\u001b[32m[0 / 1]\u001b[0m [Prepa] BazelWorkspaceStatusAction stable-status.txt\n"}}
    {"id":{"workspaceStatus":{}},"workspaceStatus":{"item":[{"key":"BUILD_EMBED_LABEL"},{"key":"BUILD_HOST","value":"mtymchuk"},{"key":"BUILD_TIMESTAMP","value":"1598888970"},{"key":"BUILD_USER","value":"mikhailtymchuk"}]}}
    {"id":{"namedSet":{"id":"0"}},"namedSetOfFiles":{"files":[{"name":"B.jar","uri":"file:///private/var/tmp/_bazel_mikhailtymchuk/3bd90847b9f03e9e5c46f99d542eb754/execroot/__main__/bazel-out/darwin-fastbuild/bin/B.jar","pathPrefix":["bazel-out","darwin-fastbuild","bin"]},{"name":"B","uri":"file:///private/var/tmp/_bazel_mikhailtymchuk/3bd90847b9f03e9e5c46f99d542eb754/execroot/__main__/bazel-out/darwin-fastbuild/bin/B","bin"]}]}}
    {"id":{"targetCompleted":{"label":"//:B","configuration":{"id":"f157fdcaf05e7672fa1bf535fbb2c3edb004ce9e9a7f6d84d9bf031454e2fb64"}}},"completed":{"success":true,"outputGroup":[{"name":"default","fileSets":[{"id":"0"}]}],"tag":["__JAVA_RULES_MIGRATION_DO_NOT_USE_WILL_BREAK__"],"importantOutput":[{"name":"B.jar","bin"]}]}}
    {"id":{"progress":{"opaqueCount":3}},"children":[{"progress":{"opaqueCount":4}},{"namedSet":{"id":"1"}}],"progress":{}}
    {"id":{"namedSet":{"id":"1"}},"namedSetOfFiles":{"files":[{"name":"libmain.jar","uri":"file:///private/var/tmp/_bazel_mikhailtymchuk/3bd90847b9f03e9e5c46f99d542eb754/execroot/__main__/bazel-out/darwin-fastbuild/bin/libmain.jar","bin"]}]}}
    {"id":{"targetCompleted":{"label":"//:main","fileSets":[{"id":"1"}]}],"importantOutput":[{"name":"libmain.jar","bin"]}]}}
    {"id":{"progress":{"opaqueCount":4}},"children":[{"progress":{"opaqueCount":5}},{"namedSet":{"id":"2"}}],"progress":{}}
    {"id":{"namedSet":{"id":"2"}},"namedSetOfFiles":{"files":[{"name":"step1_output.txt","uri":"file:///private/var/tmp/_bazel_mikhailtymchuk/3bd90847b9f03e9e5c46f99d542eb754/execroot/__main__/bazel-out/darwin-fastbuild/bin/step1_output.txt","bin"]}]}}
    {"id":{"targetCompleted":{"label":"//:step1","fileSets":[{"id":"2"}]}],"importantOutput":[{"name":"step1_output.txt","bin"]}]}}

那么，是否可以从构建事件协议（或使用其他方法）中提取目标构建开始时间？

解决方法

在控制台上，如果有帮助，您应该能够结合--subcommands（或-s）来获得此信息，该信息将在执行命令时打印命令。还有--show_timestamps，它将时间戳添加到所有发出的消息中。

这与您要的内容不同（我不确定仅通过配置就可以很轻松地增加建立事件协议的时间），但这可能有助于调试任务。