[minicoredumper] [External] Debugging corrupt tar files (invalid sparse archive member)

[Jos Hulzink (Ellips B.V.)]

> From: John Ogness <john.ogness at linutronix.de> 
> It is not a solution, but a workaround so that I can release a new bugfix version. The current behavior of creating broken tar files is not acceptable.
> However, hearing your argument about not being able to use gzip, I am wondering if falling back to avoiding tar is the correct workaround. In your case, you are expecting the dumps to be quick and if it suddenly falls back to just gzip, you will suddenly have minutes of downtime instead of seconds.
> Perhaps instead of falling back to gzip I just should log an error message saying the core file is too large? I do not want to implement too much new code for a bugfix release.

I agree that creating something that's broken is not desired. 
However, our (the?) main motivation for using minicoredumper is to significantly reduce the core dump size because the original core dump is for some reason too large to be handled. 
Falling back to gzip only would defeat that purpose in our case.

We can always choose not to update to your new bugfix release or patch the code ourselves (yay for open source!) but my suggestion for the path forward is to bail out with an error for now, add a 'known issue' and spend your precious developer time on the real fix. 

If I can be of any help with programming or testing, please let me know.

Kind regards,

Jos Hulzink