Andrea,
Did you use this exact build script (no cuda!)?  We used this build script on Fedora desktop and laptop before documenting it and GG ran all of the Operating System builds this morning to include Arch.  Line  4 below writes output to the file "log" so I am confused why you did not get this file.  Maybe start from scratch?  But if you have a slow network, downloading the opencv-20200306.tgz file may take awhile.

#!/bin/bash
( ./autogen.sh
  ./configure --with-single-user --with-booby \
    --with-opencv=sta,tar=http://cinelerra-gg.org/download/opencv/opencv-20200306.tgz
  make && make install ) 2>&1 | tee log
mv Makefile Makefile.cfg
cp Makefile.devel Makefile

On Mon, Mar 23, 2020 at 2:44 PM Andrea paz <gamberucci.andrea@gmail.com> wrote:
Compiling with opencv gives error [err -1] right after compiling
n_body cuda and, I guess, at the beginning of opencv. But no cin5log
is written, so I can't bring data.
No cuda but with opencv I have the same error.
With cuda and without opencv, the compiling is completed without errors.
If you have any requests on how to do evidence that might be useful,
let me know.