In./build.py   When I met a mistake:

G + +: internal compiler error: program cc1plus please submit a full bug report, with preprocessed source if appropriate

See < file:///usr/share/doc/gcc-7/README.Bugs> for instructions.   Waf: Leaving directory `/home/d/tarballs/ns-allinone-3.28/ns-3.28/build’

The reason is that there is not enough memory. After reading many problems solved by inputting the command line, we failed to solve them. Later, we found that it is OK to directly expand the memory outside the virtual machine

1. Open virtual machine settings

2. This virtual machine needs more memory

3. Then open the virtual machine build