hello

I need of a blueray burner so I've decided to use your software because it is the only program I believe It'is one of the most under Linux (Ubuntu) which burn CDs and DVDs without problem.
Unfortunately I believe there is a problem with tmp dir that creates some problems burning blueray. 
I'll explain you: 
To burn a blueray (for example only data) we need about 25Gb of hdd space and k3b needs to write the cache in a tmp dir (through genisoimage). Unfortunately my partition of HDD where is installed linux (and, I believe the most of, partitions of people) has not enough free space, so I specified a different folder in another HDD through the preferences section of K3b, but It doesen't work: K3b said "not enough space on temp dir" (I've only 5 Gb free space on default /tmp). So I tried to change temp, tmp, tmpdir enviroment variable without success. I think it is a problem related to genisoimage which tries to write iso on tmp default dir also if we've changed temp folder in preferences menu of k3b. I think that it is unthinkable to move tmp folder to another partition/HDD only for a program...

Any suggestions ? 
It this a bug ?

My k3b version is: 2.0.3 running on Ubuntu 16.04.5 64bit; kernel 4.4.0-133

thank you