I did change to the develop branch, the problem with ./3rdparty/getall -a persists. Several 3rd party fail to be downloaded, for example MUMPS:
Error download pkg/MUMPS_5.0.2.tar.gz
Download failed from http://mumps.enseeiht.fr/MUMPS_5.0.2.tar.gz of MUMPS_5.0.2.tar.gz
Try other site: http://pkgs.freefem.org/MUMPS_5.0.2.tar.gz
Error download pkg/MUMPS_5.0.2.tar.gz
Download 2 times failed from http://pkgs.freefem.org/MUMPS_5.0.2.tar.gz of MUMPS_5.0.2.tar.gz
Try (2 times) other site: http://104.46.50.187/pkg/MUMPS_5.0.2.tar.gz
See getall.log (10.4 KB) for full log of the download
As a matter of fact I just tried on another machine (ubuntu 20.04) that have a perfectly functionning FreeFem++ v4.14, and I get the very same error with 3rdparty/getall
It looks very much like an error that was reported previously on this thread and seemed to be due to backup server was not up-to-date according to this answer