Currently alembic is outputting the migrations names similar to this:
Generating /home/<user>/<project>/migrations/versions/2 558cb7a338e_creating_table_addre.py...done
There is a line break after "/2" splitting the path to the new migration file. It does not use current term width, and can't be turned off (without modifying alembic source). Also it should not be neccessary to add the line-breaks, most terminal emulators will break lines by themselves.