SUMMARY
Oftentimes when making an animation, full animation cache won't fit into the memory. In this case the only way to deal with that right now is rendering Image Sequence a few times (with some restarting of Krita in between), then try to render only a few frames but as an animation and using Log Viewer to see the exact ffmpeg command, then copy it, change to be a proper command and to have a proper start and end point, then execute in commandline.

My suggestion is to make it possible to run the ffmpeg command without trying to render animation frames first. That way the user will be able to do it all in GUI.

(I think right now Krita sets start frame number but not the end frame number, so theoretically first rendering all frames and then trying to render animation out of a few frames at the beginning should trigger making an animation out of the whole sentence, but I didn't try it and it's a hack anyway).


STEPS TO REPRODUCE
1. Have a huge image, big enough that the cache don't fit into the memory.
2. Try to render it. Rendering of frames will end prematurely.

OBSERVED RESULT
No way to render full animation from GUI.

EXPECTED RESULT
A way to render full animation from GUI alone.

SOFTWARE/OS VERSIONS
(Happens also in 4.2.5, which is the latest version as of now)
Krita

 Version: 4.3.0-prealpha (git 3602c72493)
 Languages: en_US
 Hidpi: false

Qt

  Version (compiled): 5.12.2
  Version (loaded): 5.12.2

OS Information

  Build ABI: x86_64-little_endian-lp64
  Build CPU: x86_64
  CPU: x86_64
  Kernel Type: linux
  Kernel Version: 4.15.0-45-generic
  Pretty Productname: Linux Mint 19.1
  Product Type: linuxmint
  Product Version: 19.1


Hardware Information

  GPU Acceleration: none
  Memory: 7771 Mb
  Number of Cores: 4
  Swap Location: /tmp