项目场景：
编译环境：ubuntu18.04
软件版本：全志SDK，安卓版本8.1.0，linux-4.9.0
问题描述：
编译SDK时遇到这个问题：
[ 97% 43/44] glob device/*/*/Android.bp
ninja: error: 'system/bt/EventLogTags.logtags', needed by 'out/target/common/obj/all-event-log-tags.txt', missing and no known rule to make it
14:47:28 ninja failed with: exit status 1
原因分析：
看log，这里是因为缺少了一个文件，system/bt/EventLogTags.logtags，我们去这个目录下查看
bell@r311:~/r311/android/system/bt$ ls
Android.bp CleanSpec.mk audio_a2dp_hw btcore build device embdrv include osi stack tools udrv vendor_libs
Android.mk README.md bta btif conf doc hci main service test types utils vnd
果然缺少这个文件，我们看文件的后缀，不清楚是什么文件，搜索一下整个目录，看看类似的文件
bell@r311:~/r311/android$ find . -name EventLogTags.logtags
./frameworks/base/core/java/android/net/EventLogTags.logtags
./frameworks/base/core/java/android/speech/tts/EventLogTags.logtags
./frameworks/base/core/java/android/webkit/EventLogTags.logtags
./frameworks/base/core/java/android/content/EventLogTags.logtags
./frameworks/base/core/java/com/android/internal/logging/EventLogTags.logtags
./frameworks/base/services/core/java/com/android/server/am/EventLogTags.logtags
./frameworks/base/services/core/java/com/android/server/EventLogTags.logtags
./frameworks/base/packages/SystemUI/src/com/android/systemui/EventLogTags.logtags
./frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/EventLogTags.logtags
./frameworks/native/services/surfaceflinger/EventLog/EventLogTags.logtags
./frameworks/opt/telephony/src/java/com/android/internal/telephony/EventLogTags.logtags
./packages/services/Telephony/src/com/android/phone/EventLogTags.logtags
./packages/providers/CalendarProvider/src/com/android/providers/calendar/EventLogTags.logtags
./packages/providers/ContactsProvider/src/com/android/providers/contacts/EventLogTags.logtags
./packages/apps/QuickSearchBox/src/com/android/quicksearchbox/EventLogTags.logtags
./packages/apps/Settings/src/com/android/settings/EventLogTags.logtags
./packages/apps/TimeZoneUpdater/src/main/com/android/timezone/updater/EventLogTags.logtags
./system/core/storaged/EventLogTags.logtags
./system/core/libsysutils/EventLogTags.logtags
bell@r311:~/r311/android$ cat ./frameworks/base/core/java/android/net/EventLogTags.logtags
# See system/core/logcat/event.logtags for a description of the format of this file.
option java_package android.net
50080 ntp_success (server|3),(rtt|2),(offset|2)
50081 ntp_failure (server|3),(msg|3)
解决方案：
从cat的结果看，这个EventLogTags.logtags文件似乎不是很重要，我们在system/bt目录下touch 一个EventLogTags.logtags文件，再次编译，问题解决！
