Chrome Version: ToT
OS: Chrome OS

All toolchain builders failed with: 
@@@STEP_LINK@Builder documentation@http://www.chromium.org/chromium-os/build/builder-overview#TOC-Continuous@@@
10:01:42: INFO: Running cidb query on pid 19869, repr(query) starts with 'SELECT NOW()'
10:01:42: INFO: Running cidb query on pid 19869, repr(query) starts with <sqlalchemy.sql.expression.Insert object at 0x7f846a485590>
10:01:42: ERROR: Error: (IntegrityError) (1062, "Duplicate entry '8968103418167764992' for key 'buildbucket_id_index'") 'INSERT INTO `buildTable` (master_build_id, buildbot_generation, builder_name, waterfall, build_number, build_config, bot_hostname, start_time, deadline, important, buildbucket_id) VALUES (%s, %s, %s, %s, %s, %s, %s, CURRENT_TIMESTAMP, %s, %s, %s)' (1860550, 1, 'amd64-llvm-next-toolchain', 'chromeos', 388, u'amd64-llvm-next-toolchain', 'cros-beefy272-c2.c.chromeos-bot.internal', datetime.datetime(2017, 9, 19, 6, 53, 24), True, '8968103418167764992')
 If the buildbucket_id to insert is duplicated to the buildbucket_id of an old build and the old build was canceled because of a waterfall master restart, please ignore this error. Else, the error needs more investigation. More context:  crbug.com/679974  and  crbug.com/685889 


What steps will reproduce the problem?

Here is an example: 
https://chromegw.corp.google.com/i/chromeos/builders/arm64-llvm-next-toolchain/builds/387/steps/BuildStart/logs/stdio

and 

https://chromegw.corp.google.com/i/chromeos/builders/amd64-llvm-next-toolchain/builds/388/steps/BuildStart/logs/stdio

all the toolchain builders failed with that this morning. 

https://chromegw.corp.google.com/i/chromeos/waterfall?builder=master-toolchain&builder=amd64-llvm-next-toolchain&builder=arm-llvm-next-toolchain&builder=arm64-llvm-next-toolchain&titles=off&reload=30

I see the error message refers to this issue:  crbug.com/679974 

And I can see that previous iteration of the builders was "interrupted" (purple color) so maybe I should be ignoring this error.

But, it does not sound right to ignore. The builder yesterday was "interrupted" and the one today failed because of this error. I don't think this should be expected behavior. It is just another day of testing that was not done. So, every interrupt on one day means a failure on the next day?

assigning to Sheriff (akeshet) for clarification.