make -j 4 make: *** No targets specified and no makefile found. Stop. about librecad_3

[tormodvolden]

Never use "sudo" for compiling. Use it only for installing packages (apt install) and in some cases for "make install" (if it fails with permission issues without it, because it installs stuff to system locations).

"make -j 4 make" is wrong, it should be "make -j 4"

The instructions on https://github.com/LibreCAD/LibreCAD_3/wiki/Building work fine, I just tested them on Ubuntu 20.04. Two packages were missing in the Debian/Ubuntu/Mint list but they have now been added.

[lordofbikes]

But when i run:
make -j 4 make

The difference between build instructions and your command is obviously one make too much.
Run make -j 4, this should work.
The error is about the second make which is interpreted as target, for which no rule exists in the makefile.

[jonadem]

Did you run cmake .. before ?
Did it work without issue ?
Normally the last lines should look like :

-- Configuring done
-- Generating done
-- Build files have been written to: /YOUR_PATH/LibreCAD_3/build