David, looks like this build was tested in regular tot testing yesterday. Was this seen?

Not on dev no. 

What device ?

We reproduced on a link and lulu.

Let me double check we AUd from the same build this morning 

We're crashing somewhere after signing-in. This only happens with an account registered before the update so my guess is that the crash is related to profile migration.

Not reproducee on Minnie. Was reproduced on Samus 

looks like dup of https://bugs.chromium.org/p/chromium/issues/detail?id=711207 ?

Cannot repro on falco, chell, paine -- build 9460.0.0/59.0.3068.1

Got a symbolized stack trace (full info attached). This crash is in sync code so I suspect is is different from  issue 711207 .
    
     0  libstdc++.so.6.0.20!std::string::assign(std::string const&) [basic_string.h : 293 + 0x0]
     1  chrome!GetRawKey [basic_string.h : 555 + 0xb]
     2  chrome!ExportKeys [nigori.cc : 241 + 0x5]
     3  chrome!Cryptographer [cryptographer.cc : 38 + 0x1b]
     4  chrome!<name omitted> [ptr_util.h : 56 + 0xb]
     5  chrome!Init [sync_encryption_handler_impl.cc : 305 + 0x8]
     6  chrome!DoInitialProcessControlTypes [sync_backend_host_core.cc : 372 + 0x6]
     7  chrome!ConfigureSyncer [sync_manager_impl.cc : 202 + 0x6]
     8  chrome!OnInitializationComplete [sync_backend_host_core.cc : 165 + 0x10]
     9  chrome!NotifyInitializationSuccess [sync_manager_impl.cc : 333 + 0x16]
    10  chrome!Init [sync_manager_impl.cc : 328 + 0xc]
    11  chrome!DoInitialize [sync_backend_host_core.cc : 332 + 0x3]
    12  chrome!Run [bind_internal.h : 214 + 0x9]
    13  chrome!RunTask [callback.h : 91 + 0x3]
    14  chrome!RunTask [message_loop.cc : 423 + 0x10]
    15  chrome!DoWork [message_loop.cc : 434 + 0xb]
    16  chrome!base::MessagePumpDefault::Run(base::MessagePump::Delegate*) + 0x19
    17  chrome!Run [run_loop.cc : 37 + 0x5]
    18  chrome!ThreadMain [thread.cc : 333 + 0xc]
    19  chrome!ThreadFunc [platform_thread_posix.cc : 71 + 0x8]
    20  libpthread-2.23.so!start_thread [pthread_create.c : 333 + 0x11]
    21  libc-2.23.so!clone + 0x6d

Deleted: symbols.txt 142 KB

symbols.txt 142 KB View Download

Passing to pnoland@ who has been touching sync code recently. Possibly related to issue 707967?

I'm assuming that "3680.1" in the original report is a typo and that it should read "3068.1" The issue is present in 3068.1 but should be fixed in canary builds >=3068.4. ChromeOS just branched at 3071, which contains the fix, so that build should be fine. I don't think there's anything else to do at this point except wait for the new canary build?

Ok. Will leave this open for verification on next M59 dev testing. Thanks!

Prasanthi was able to  recover and sign in on samus using build 9460.4.0/59.0.3071.8