After following this answer to remove an unwanted layer from the image I removed the build/tmp directory and tried to run bitbake again. I got this error:
PermissionError: [Errono 13] Perrmission denied:'/tmp'
I tried to change permissions of the directory chomd -R 777 build/tmp/ and run bitbake again, but the error persists. I also tried to run the sstate-cache-management.sh, but it has no effect.
Just for clarity, it seems that /tmp directory is created again during bitbak command, but it still fails after parsing all the recipes.
What can I do to still save my progress so far? I can always start from scratch, but I really don't want to build the kernel again.
I figured out the answer, I accidentally deleted root tmp folder, not the folder in build directory. After creating it again and setting proper permissions, the build process works again.