Erik, Ken: any idea what may be going on here from the Mac system log?

Not sure. There are errors coming from GoogleSoftwareUpdate, which seems suspicious but I don't think should block Chrome from launching.

We've seen intermittent failures to start Chrome for at least a few months in the Telemetry-based tests running on the GPU bots. In order to make progress we added retries of the browser launch to that other test harness. This is a poor solution and it would be better to get to the bottom this. However, without a minidump and stack trace it's impossible to guess what's happening.

Log excerpt:

Apr  6 04:12:45 build125-b1 ksadmin[616]: KSKeyedPersistentStore store directory does not exist. [com.google.UpdateEngine.CommonErrorDomain:501 - '/Library/Google/GoogleSoftwareUpdate/TicketStore' - 'KSKeyedPersistentStore.m:372']
Apr  6 04:12:45 build125-b1 ksadmin[616]: KSPersistentTicketStore failed to load tickets. (productID: com.google.Chrome) [com.google.UpdateEngine.CoreErrorDomain:1051 - '/Library/Google/GoogleSoftwareUpdate/TicketStore/Keystone.ticketstore'] (KSKeyedPersistentStore store directory does not exist. - '/Library/Google/GoogleSoftwareUpdate/TicketStore' [com.google.UpdateEngine.CommonErrorDomain:501])
Apr  6 04:12:45 build125-b1 ksadmin[616]: ksadmin cannot access the ticket store:<KSUpdateError:0x100213f00
		domain="com.google.UpdateEngine.CoreErrorDomain"
		code=1051
		userInfo={
			function = "-[KSProductKeyedStore(ProtectedMethods) errorForStoreError:productID:message:timeoutMessage:]";
			date = 2017-04-06 11:12:45 +0000;
			productids = {(
				"com.google.Chrome"
			)};
			filename = "KSProductKeyedStore.m";
			line = 91;
			NSFilePath = "/Library/Google/GoogleSoftwareUpdate/TicketStore/Keystone.ticketstore";
			NSUnderlyingError = <KSError:0x100704800
				domain="com.google.UpdateEngine.CommonErrorDomain"
				code=501
				userInfo={
					date = 2017-04-06 11:12:45 +0000;
					line = 372;
					filename = "KSKeyedPersistentStore.m";
					function = "-[KSKeyedPersistentStore(PrivateMethods) validateStorePath]";
					NSFilePath = "/Library/Google/GoogleSoftwareUpdate/TicketStore";
					NSLocalizedDescription = "KSKeyedPersistentStore store directory does not exist.";
				}
			>;
			NSLocalizedDescription = "KSPersistentTicketStore failed to load tickets.";
		}
	>
Apr  6 04:12:45 build125-b1 ksadmin[617]: Using ticket store: <KSPersistentTicketStore:0x100606290 store=<KSKeyedPersistentStore:0x100607430
		path="/Users/chrome-bot/Library/Google/GoogleSoftwareUpdate/TicketStore/Keystone.ticketstore"
		lockFile=<KSLockFile:0x1003109e0
			path="/Users/chrome-bot/Library/Google/GoogleSoftwareUpdate/TicketStore/Keystone.ticketstore.lock"
			locked=NO
		>
	>>.

Looks like 4 failures in the last 1000 tasks on this bot.   Maybe a flake?

This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Assigning to Ned to close this out.