I can take exactly one exposure from the Nikon D5100 but anything after (either in the sequence or waiting and then new sequences), causes a indi_gphoto_ccd crash. Here's the debug info. I'm running kstars-bleeding and latest indilib from the PPA in the Ekos VM.

Starting program: /usr/bin/indi_gphoto_ccd
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
2016-09-20T05:46:16: Client 0: new arrival from 127.0.0.1:40318 - welcome!
2016-09-20T05:47:19: Driver indi_gphoto_ccd: Empty input file
2016-09-20T05:47:19: Driver indi_gphoto_ccd: stderr EOF
2016-09-20T05:47:19: Driver indi_gphoto_ccd: restart #3
2016-09-20T05:47:19: Driver indi_gphoto_ccd: pid=2893 rfd=3 wfd=7 efd=8
2016-09-20T05:47:19: Driver indi_gphoto_ccd: snooping on Telescope Simulator.EQUATORIAL_EOD_COORD
2016-09-20T05:47:19: Driver indi_gphoto_ccd: snooping on Telescope Simulator.TELESCOPE_INFO
2016-09-20T05:47:19: Driver indi_gphoto_ccd: snooping on CCD Simulator.FILTER_SLOT
2016-09-20T05:47:19: Driver indi_gphoto_ccd: snooping on CCD Simulator.FILTER_NAME


DEBUG 107.370564 sec : Requested CCD Frame is ( 0, 0) (1280 x 1024)
DEBUG 107.371431 sec : Starting exposure (exptime: 1 secs, mirror lock: 0)
DEBUG 107.371521 sec : Mutex locked
DEBUG 107.371552 sec : Setting radio/menu widget capturetarget: 0 (Internal RAM)
DEBUG 107.372300 sec : Setting new configuration OK.
DEBUG 107.372383 sec : Using camera predefined exposure ranges.
DEBUG 107.372397 sec : Finding optimal exposure setting for 1 seconds...
DEBUG 107.372406 sec : Best match: 1 seconds Index: 36
DEBUG 107.372417 sec : Setting radio/menu widget shutterspeed2: 36 (1)
DEBUG 107.372832 sec : Setting new configuration OK.
DEBUG 107.372852 sec : Using predefined exposure time: 1 seconds
DEBUG 107.377667 sec : Exposure started
INFO 107.377743 sec : Starting 1 sec exposure
DEBUG 108.378090 sec : Reading exposure
DEBUG 108.378128 sec : Exposure complete
DEBUG 108.378140 sec : Retval: 0
DEBUG 108.378147 sec : Downloading //capt0000.jpg
DEBUG 108.378227 sec : Retval: -108
DEBUG 108.378251 sec : Downloaded 0x0 (preview 0x0)
DEBUG 108.378263 sec : Deleting.
DEBUG 108.378278 sec : Retval: -108
DEBUG 108.378306 sec : Setting radio/menu widget shutterspeed2: 36 (1)
DEBUG 108.378862 sec : Setting new configuration OK.
INFO 108.378890 sec : Exposure done, downloading image...

Thanks for the report, will investigate the (--108) return value but I have no Nikon to test with now, we'll see.

This might be a problem in the gphoto code as well, I'll double check that. Let me know if you want me to compile any source locally since I can test against the camera, I'm good for it (developer and 15+ years sys/net admin). Looking to get involved in the Indi project anyway that I can. Very thrilled at what you're doing here!

So the error happens here:
So why it's failing to download I'm not sure. Maybe folder name issue? At any rate, I added a return value now so that it fails instead of crashing if there is no image to download.

Haven't had too much time to look at it yet, but gphoto works (--interval 2 --frames 5). The camera is set to RAW + Normal which is .NEF and .JPG.

I think this has to do with looking for/expecting the wrong filename from the camera, either because of a conflict between Ekos settings (FITS/Native) and the camera, or because of the incorrect file extension (.fits instead of .nef) or not incrementing the file name.

I actually found I can flip between the reported crash and a file not found error by toggling the FITS/Native settings. I'm not sure which config leads to which state yet, I'll look later.

I've attached the gphoto debug log with the long hex data stripped, maybe some clues? THANK YOU

IIRC, the INDI Gphoto driver doesn't work if you select two image types. Try selecting just one and see if that makes a difference.

Thank you for the help thus far. I am by the first issue, which is the inability to take multiple exposures. To solve that I needed to select either JPEG (Normal) by itself or NEF (RAW) by itself. Once I do that I can take multiple 1-2 second exposures as often as I would like.

The next problem is longer exposures. Anything long than 2 or 3 seconds causes the retval -108 issue again. The interesting thing is that in every case it's always look for the filename of the last capture file. When I'm restarting a task list for 1 second exposures it's constantly incrementing the filename. It's only when I add a longer exposure does it seem to forget what capture file it's supposed to ask for.

The behavior is slightly different if I restart everything and start the first exposure with a 3 second or longer exposure. When I do that instead of seeing "Downloading //<capfile>.nef, I see "Download /", which of course fails and then different error codes (100 followed by a 107 I believe).

It's like longer exposures in the sequence queue lose track (or the Nikon isn't telling them properly) which capture file they were supposed to be asking for. Also, this happens when I use either FITS or Native node, that doesn't seem to matter. Probably also worth noting that in several of these cases I have to restart the camera too (once a capture retrieval problem occurs).

DEBUG 103.276850 sec : Setting radio/menu widget capturetarget: 0 (Internal RAM)
DEBUG 103.277192 sec : Setting new configuration OK.
DEBUG 103.277208 sec : Using camera predefined exposure ranges.
DEBUG 103.277216 sec : Finding optimal exposure setting for 1 seconds...
DEBUG 103.277223 sec : Best match: 1 seconds Index: 36
DEBUG 103.277230 sec : Setting radio/menu widget shutterspeed2: 36 (1)
DEBUG 103.297119 sec : Setting new configuration OK.
DEBUG 103.297214 sec : Using predefined exposure time: 1 seconds
DEBUG 103.297242 sec : Exposure started
INFO 103.297262 sec : Starting 1 sec exposure
DEBUG 104.297397 sec : Reading exposure
DEBUG 108.746417 sec : Exposure complete
DEBUG 108.746915 sec : Retval: 0
DEBUG 108.746929 sec : Downloading //capt0007.nef
DEBUG 108.760566 sec : Retval: 0
DEBUG 108.763691 sec : Downloaded 4928x3264 (preview 160x120)
DEBUG 108.764861 sec : Deleting.
DEBUG 108.764955 sec : Retval: 0
DEBUG 108.765050 sec : Setting radio/menu widget iso: 15 (3200)
DEBUG 108.765481 sec : Setting new configuration OK.
DEBUG 108.765578 sec : Setting radio/menu widget shutterspeed2: 41 (3)
DEBUG 108.820322 sec : Setting new configuration OK.
DEBUG 108.820415 sec : Exposure done, downloading image...
DEBUG 121.409137 sec : Requested CCD Frame is ( 0, 0) (1280 x 1024)
ERROR 121.409203 sec : Subframing is only supported in FITS transport mode.
DEBUG 121.409492 sec : Starting exposure (exptime: 5 secs, mirror lock: 0)
DEBUG 121.409511 sec : Mutex locked
DEBUG 121.409524 sec : Setting radio/menu widget iso: 15 (3200)
DEBUG 121.409917 sec : Setting new configuration OK.
DEBUG 121.409929 sec : Setting radio/menu widget capturetarget: 0 (Internal RAM)
DEBUG 121.410262 sec : Setting new configuration OK.
DEBUG 121.410272 sec : Using camera predefined exposure ranges.
DEBUG 121.410280 sec : Finding optimal exposure setting for 5 seconds...
DEBUG 121.410287 sec : Best match: 5 seconds Index: 43
DEBUG 121.410294 sec : Setting radio/menu widget shutterspeed2: 43 (5)
DEBUG 121.434852 sec : Setting new configuration OK.
DEBUG 121.435008 sec : Using predefined exposure time: 5 seconds
DEBUG 121.435052 sec : Exposure started
INFO 121.435114 sec : Starting 5 sec exposure
DEBUG 122.435205 sec : Capture in progress. Time left 4
DEBUG 123.435568 sec : Capture in progress. Time left 2
DEBUG 124.435777 sec : Capture in progress. Time left 1
DEBUG 125.436570 sec : Reading exposure
DEBUG 227.602508 sec : Exposure complete
DEBUG 227.602743 sec : Retval: 0
DEBUG 227.602972 sec : Downloading //capt0007.nef
DEBUG 227.603113 sec : Retval: -108
DEBUG 227.603222 sec : Downloaded 0x0 (preview 0x0)
DEBUG 227.603381 sec : Deleting.
DEBUG 227.603542 sec : Retval: -108
DEBUG 227.603643 sec : Setting radio/menu widget iso: 15 (3200)
DEBUG 227.604194 sec : Setting new configuration OK.
DEBUG 227.604364 sec : Setting radio/menu widget shutterspeed2: 41 (3)

I don't have this problem in gphoto, though it seems to reset the filename and doesn't quite have the same sequence queue capabilities as Ekos, unless one scripts it.

$ gphoto2 --interval=5 --frames=5 --force-overwrite --capture-image-and-download
Time-lapse mode enabled (interval: 5s).
Capturing frame #1/5...
New file is in location /capt0000.nef on the camera
Saving file as capt0000.nef
Deleting file /capt0000.nef on the camera
Waiting for next capture slot 1 seconds...
Capturing frame #2/5...
New file is in location /capt0001.nef on the camera
Saving file as capt0001.nef
Deleting file /capt0001.nef on the camera
Waiting for next capture slot 2 seconds...
Capturing frame #3/5...
New file is in location /capt0002.nef on the camera
Saving file as capt0002.nef
Deleting file /capt0002.nef on the camera
Waiting for next capture slot 1 seconds...
Capturing frame #4/5...
New file is in location /capt0003.nef on the camera
Saving file as capt0003.nef
Deleting file /capt0003.nef on the camera
Waiting for next capture slot 2 seconds...
Capturing frame #5/5...
New file is in location /capt0004.nef on the camera
Saving file as capt0004.nef
Deleting file /capt0004.nef on the camera