UserAgent: Mozilla/5.0 (X11; CrOS x86_64 10718.50.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.59 Safari/537.36
Platform: 10718.50.0 (Official Build) beta-channel cyan

Steps to reproduce the problem:
1. Open "Setting" > "About Chrome OS"
2. Open "Detailed build information" > "Change Channel" > "Developer - unstable"
3. System will automatically update
4. Update failed

What is the expected behavior?
Update success

What went wrong?
1. Try using update_engine_client (Developer mode turned on)
2. Check client log at file:///var/log/update_engine/
3. Found that the problem is related to firmware updater
4. The founded evidence:
> Starting firmware updater (//usr/sbin/chromeos-firmwareupdate --mode=autoupdate)
> Command: //usr/sbin/chromeos-firmwareupdate --mode=autoupdate
> Starting Google_Cyan firmware updater v4 (autoupdate)...
>  - Updater package: [RO:Google_Cyan.7287.57.100 RW:Google_Cyan.7287.57.180 / EC:cyan_v1.1.3571-7ae3bf3]
>  - Current system:  [RO:Google_Cyan.7287.57.100 , ACT:Google_Cyan.7287.57.165 / EC:cyan_v1.1.3575-c3321a1]
>  - Write protection: Hardware: ON, Software: Main=ON
> Firmware update available: Google_Cyan.7287.57.180. 
>  * invoke: flashrom -p host -r _current/bios.bin
>  * invoke: flashrom -p host --fast-verify -w bios.bin -i RW_SECTION_B
>  Execution failed (1): flashrom -p host --fast-verify -w bios.bin -i RW_SECTION_B
>  Messages:
> Calibrating delay loop... OK.
> coreboot table found at 0x7cc22000.
> Erasing and writing flash chip... FAILED
> flashrom v0.9.9  : d2da987 : Jun 21 2018 23:31:30 UTC on Linux 3.18.0-17859-g5fb5517a15a9 (x86_64)
> Mapping BYT IBASE at 0xfed08000, unaligned size 0x200.
> Mapping BYT SBASE at 0xfed01000, unaligned size 0x200.
> Block protection could not be disabled!
> spi_block_erase_52 failed during command execution at address 0x318000
> ERASE FAILED!
> FAILED!
> Uh oh. Erase/write failed. Checking if anything changed.
> Your flash chip is in an unknown state.
> Get help on IRC at irc.freenode.net (channel #flashrom) or
> mail flashrom@flashrom.org with FAILED: your board name in the subject line!

6. This problem didn't happened in BETA to BETA update, only occur in BETA to DEV update

Did this work before? N/A 

Chrome version: 68.0.3440.59  Channel: beta
OS Version: 10718.50.0
Flash Version: 30.0.0.134 

What's happening?
How do I save my device?
 

Deleted: update_engine.20180716-071748(beta to dev).txt 54.2 KB

update_engine.20180716-071748(beta to dev).txt 54.2 KB View Download

Deleted: update_engine.20180716-070658(beta to beta).txt 50.7 KB

update_engine.20180716-070658(beta to beta).txt 50.7 KB View Download