I'm trying to build custom image, but "./scripts/feeds update -a" was stopping with next output:
root@Home-Ubuntu:/media/sergey/Data/openwrt# ./scripts/feeds update -a
Can't exec "make": No such file or directory at ./scripts/feeds line 22.
Use of uninitialized value in split at ./scripts/feeds line 22.
Use of uninitialized value $mkver in pattern match (m//) at ./scripts/feeds line 24.
Use of uninitialized value $mkver in pattern match (m//) at ./scripts/feeds line 25.
Use of uninitialized value $mkver in split at ./scripts/feeds line 27.
Use of uninitialized value $mkv1 in numeric ge (>=) at ./scripts/feeds line 28.
Use of uninitialized value $mkv1 in numeric eq (==) at ./scripts/feeds line 28.
Unsupported version of make found: make
Same result for local account, different folder and PC.
That sounds like you don't have the normal "make" installed, as that is requested (as "mk") on line 22:
Have you installed all prerequisites?
Personally I use this for ubuntu 18.04:
### Prerequisites for buildroot sudo apt-get install build-essential subversion libncurses5-dev zlib1g-dev sudo apt-get install gawk gcc-multilib flex git-core gettext libssl-dev ### Prerequisite on Ubuntu 17.10+ as it has python3 by default sudo apt-get install python