My 1.8.1 IDE is still using .arduino15 folder

After enabling the "verbose" option for compiling sketch, I noticed that the 1.8.1 IDE is still using the hidden folder ".arduino15/" in the home directory of my Ubuntu 16.04 system:

Detecting libraries used...
"/home/giulio/[b].arduino15/[/b]packages/arduino/tools/avr-gcc/4.9.2-atmel3.5.4-arduino2/bin/avr-g++" -c -g -Os.......
.
.
.
Generating function prototypes...
"/home/giulio[b]/.arduino15/[/b]packages/arduino/tools/avr-gcc/4.9.2-atmel3.5.4-arduino2/bin/avr-g++" -c -g -Os -w.......
.
.
.

Is this normal?

Yes. that folder is used by 1.5.x and later.

ok

Do you want it to not use that folder?

Honestly I don't care about that until the IDE compiler works fine and the folder contains updated data aligned with the last version.