Apple Mail crashes on launch if connection logging is enabled

This was a fun one.  Mail started crashing on launch for absolutely no apparent reason – nothing had changed to its config or similar in a long time.  The crash logs were all fingering an identical culprit – -[IMAPTaskManager secondaryIdleMailboxName] called on the wrong GCD queue:

Process: Mail [19884]
Path: /Applications/
Version: 11.3 (3445.6.18)
Build Info: Mail-3445006018000000~4
Code Type: X86-64 (Native)
Parent Process: ??? [1]
Responsible: Mail [19884]
User ID: …

Date/Time: 2018-04-19 16:44:45.717 -0700
OS Version: Mac OS X 10.13.4 (17E199)
Report Version: 12
Anonymous UUID: …

Sleep/Wake UUID: …

Time Awake Since Boot: 94000 seconds
Time Since Wake: 530 seconds

System Integrity Protection: enabled

Crashed Thread: 13 Dispatch queue: Task Manager Serialization Queue (QOS: UNSPECIFIED)

Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000

Application Specific Information:
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'This method should only be called on the serialization queue'
terminating with uncaught exception of type NSException
abort() called

Application Specific Backtrace 1:
0 CoreFoundation 0x00007fff55da96bb __exceptionPreprocess + 171
1 libobjc.A.dylib 0x00007fff7d4c1942 objc_exception_throw + 48
2 CoreFoundation 0x00007fff55daf2a2 +[NSException raise:format:arguments:] + 98
3 Foundation 0x00007fff57ee7340 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 193
4 IMAP 0x00007fff6fe88959 -[IMAPTaskManager secondaryIdleMailboxName] + 216
5 IMAP 0x00007fff6fe880cb -[IMAPTask mailboxIsUserVisibleUsingDataSource:] + 180
6 IMAP 0x00007fff6fe6ab68 -[IMAPMailboxSyncTask _nextNetworkPriorityAndOperation:reservedNetworkPriority:] + 164
7 IMAP 0x00007fff6fe6c4ba -[IMAPMailboxSyncTask recalculatePriorities] + 398
8 IMAP 0x00007fff6fe67dd9 -[IMAPMailboxSyncTask initWithDataSource:taskManager:imapMailbox:fromStatus:forceFullSync:] + 766
9 IMAP 0x00007fff6fe931f7 -[IMAPTaskManager _syncMailboxWithDataSource:withIMAPMailbox:fromStatus:forceFullSync:userInitiated:] + 370
10 IMAP 0x00007fff6fe92e68 -[IMAPTaskManager syncMailboxWithDataSource:withIMAPMailbox:fromStatus:forceFullSync:userInitiated:] + 240
11 IMAP 0x00007fff6fe9631a -[IMAPTaskManager didAddMessagesWithUnknownUID:toDataSource:] + 872
12 Foundation 0x00007fff57e4a5df __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ + 7
13 Foundation 0x00007fff57e4a441 -[NSBlockOperation main] + 68
14 Foundation 0x00007fff57e488ee -[__NSOperationInternal _start:] + 778
15 Foundation 0x00007fff57e44917 __NSOQSchedule_f + 369
16 libdispatch.dylib 0x00007fff7e09ee08 _dispatch_client_callout + 8
17 libdispatch.dylib 0x00007fff7e0b1ed1 _dispatch_continuation_pop + 472
18 libdispatch.dylib 0x00007fff7e0a9783 _dispatch_async_redirect_invoke + 703
19 libdispatch.dylib 0x00007fff7e0a09f9 _dispatch_root_queue_drain + 515
20 libdispatch.dylib 0x00007fff7e0a07a5 _dispatch_worker_thread3 + 101
21 libsystem_pthread.dylib 0x00007fff7e3f0169 _pthread_wqthread + 1387
22 libsystem_pthread.dylib 0x00007fff7e3efbe9 start_wqthread + 13

Long story short, the issue turns out to be having connection logging enabled.  That’d been turned on many months before in order to debug a different stupid Mail bug, and had been simply left on (deliberately IIRC, since Mail tends to bug-out quite often, so why not have logs already available when it comes time to debug it yet again?).

Connection logging is enabled or disabled by opening the “Connection Doctor” (Window menu > Connection Doctor) and using the checkbox titled “Log Connection Activity”.

So how do you get to that checkbox when Mail crashes on launch?  Well, in this specific instance I was able to disable all mail accounts via System Preference’s Accounts pane, launch Mail, disable logging, quit Mail, re-enable all mail accounts via System Preferences, and then relaunch Mail to have it finally actually work.

From even just brief web searching, it’s clear that this issue has been present and well-known in Mail for a really long time.  Sigh.  Apple’s protestations that they care about software quality, or the Mac, are relentlessly undermined by their actual actions.

macOS 10.12.2 appears to have brought with it some GPU issues

I run Einstein@Home, using both CPU cores & my GPU.  Other than a few month period where Einstein@Home was issuing broken GPU work units, I’ve been successfully doing this for years, I think.  Longer than I can really remember, in any case.

It appears, however, that 10.12.2 has introduced some serious issues impacting those GPU tasks.  While there’s always been occasional issues with performance while running these GPU tasks – e.g. Amazon streaming video drops frames – I’ve not had any major complaints.

Now, however, I have this:

Screen shot showing massive graphics corruptionThat’s what I get when I render a Nikon NEF file, pretty much anywhere in the system.

The exact symptoms of the issue seem to vary depending on where & what type of NEF file I render – e.g. rendering them in Preview mostly constraints the graphics corruption to Preview, and doesn’t readily lead to the whole system hanging.  Using the Finder for its previews, or Quicklook, however, very quickly leads to massive graphics corruption and, for Nikon D7100 NEFs, quickly hangs the system entirely.  Oddly, Nikon D500 NEFs don’t tend to cause immediate system hangs, but will prevent the system restarting or shutting down – it ends up hung at a black screen, after seemingly closing the window server, with a very consistent pattern of corruption and a frozen mouse cursor.

I never saw this, or anything like it, prior to the 10.12.2 update.  Sigh.

FWIW, the particular work unit in question triggering this right now is:

Screen shot of the Einstein@Home work unit properties dialog

Yay! An actual outage! I’m a real blog now!

I woke up this morning to find that my website – this one – had gone down only a few minutes earlier.  The host’s website,, was acting flaky and not letting me log in either, so I figured it was a widespread issue on their end.

A few hours later, was working again, but my site wasn’t.  Sad panda.

Long story short, I used up all the disk space – and by “I”, I mean something – still haven’t figured out what, yet.  Apparently when you use up all the space, that simply kills the VM without any notification (their dashboard for my VM still claimed it was running just fine, no problems detected, which was obvious crap).

That said, their tech support identified the problem quickly and were ultimately able to rectify things for me (after first suggesting I delete some stuff myself, which I tried only to find that when your Gandi VM is wedged in this state, you can’t log in via SSH nor delete anything via SFTP, and those are your only two means for deleting any files…).

As far as I can recall, this is the first time my site’s actually been down in the ~four years I’ve hosted with them (other than a few errors on my part when messing with WordPress etc).