I had the same issue that the make expects the directory ‘build-1’ instead of ‘build-linux’.

But no problem: add the directory ‘build-1’ at the same level where ‘build-linux’ is and restart make. The directory build-1 is never used for make activities, no files are stored inside.

Thanks for this cool tutorial, it worked at the first shot.

Thumbs up !

I have a nextcloudpi running under docker. A 5 min task to load an start the server:
https://ownyourbits.com/2017/11/15/nextcloudpi-dockers-for-x86-and-arm/