setfacl(1) -d -m g::rwx $HOME/projects/def-profname/group_writable
set file access control lists
-d, --default
    All operations apply to the Default ACL. Regular ACL entries in the input set are promoted to Default
    ACL  entries.  Default  ACL  entries  in  the  input  set are discarded. (A warning is issued if that
    happens).
source manpages: setfacl