It seems to have a new side effect which I haven't noticed upfront as it does not produce logging in Dovecot:
Program terminated with signal SIGSEGV, Segmentation fault.
#0 io_loop_extract_notify_fd (ioloop=0x563456973540) at ioloop-notify-inotify.c:224
224 ioloop-notify-inotify.c: No such file or directory.
(gdb) bt full
#0 io_loop_extract_notify_fd (ioloop=0x563456973540) at ioloop-notify-inotify.c:224
ctx = 0x0
io = <optimized out>
fd = <optimized out>
new_inotify_fd = <optimized out>
#1 0x00007f30bc2b740d in mailbox_watch_extract_notify_fd (box=0x563456973fc8, reason_r=reason_r@entry=0x7ffea4ebcfe8) at mailbox-watch.c:144
ioloop = 0x563456973540
file = 0x0
io = 0x91e89a45d153b800
iop = <optimized out>
temp_ios = {arr = {buffer = 0x5634566690e8, element_size = 8}, v = 0x5634566690e8, v_modifiable = 0x5634566690e8}
ret = <optimized out>
failed = false
#2 0x0000563456150418 in imap_client_hibernate (_client=_client@entry=0x7ffea4ebd0d0) at imap-client-hibernate.c:221
client = 0x56345668be48
state = 0x563456a4bf20
error = 0x7f30bbfcbb02 "H\211\005\027\353("
ret = 1
fd_notify = -1
fd_hibernate = -1
__FUNCTION__ = "imap_client_hibernate"
#3 0x0000563456146984 in idle_hibernate_timeout (ctx=0x5634566b6170) at cmd-idle.c:191
client = 0x56345668be48
#4 0x00007f30bbfe09f2 in io_loop_handle_timeouts_real (ioloop=0x5634566719b0) at ioloop.c:567
timeout = 0x56345697e090
item = 0x56345697e090
tv = {tv_sec = 0, tv_usec = 0}
tv_call = {tv_sec = 1500487741, tv_usec = 857399}
t_id = 3
#5 io_loop_handle_timeouts (ioloop=ioloop@entry=0x5634566719b0) at ioloop.c:580
_data_stack_cur_id = 2
#6 0x00007f30bbfe2153 in io_loop_handler_run_internal (ioloop=ioloop@entry=0x5634566719b0) at ioloop-epoll.c:196
ctx = 0x5634566734d0
io = <optimized out>
tv = {tv_sec = 0, tv_usec = 32654}
events_count = 5
msecs = <optimized out>
ret = 0
i = <optimized out>
j = <optimized out>
call = <optimized out>
__FUNCTION__ = "io_loop_handler_run_internal"
#7 0x00007f30bbfe0bdc in io_loop_handler_run (ioloop=ioloop@entry=0x5634566719b0) at ioloop.c:648
No locals.
#8 0x00007f30bbfe0d88 in io_loop_run (ioloop=0x5634566719b0) at ioloop.c:623
__FUNCTION__ = "io_loop_run"
#9 0x00007f30bbf666d3 in master_service_run (service=0x563456671850, callback=<optimized out>) at master-service.c:666
No locals.
#10 0x00005634561421d3 in main (argc=1, argv=0x5634566715e0) at main.c:491
set_roots = {0x56345636d6c0 , 0x7f30bc7b0540 , 0x0}
login_set = {auth_socket_path = 0x563456669048 "\001", postlogin_socket_path = 0x0, postlogin_timeout_secs = 60, callback = 0x56345615d2b0 , failure_callback = 0x56345615cbf0 ,
request_auth_token = 1}
service_flags = <optimized out>
storage_service_flags = <optimized out>
username = 0x0
auth_socket_path = 0x563456166074 "auth-master"
c = <optimized out>