When running from outside of a virtualenv, poetry export will create a virtualenv before running the command.
This has two issues:

• creating a virtual env is slow and makes the command leaves behind unnecessary resources
• creating a virtual env prints Creating virtualenv ... to stdout, which means it not possible to use the command's stdout to put the output in a arbitrary location (see --output relative to the project directory even when running from another directory #77 )

On top of that creating the virtualenv is not needed for this command (I've tried with poetry config --local virtualenvs.create true and it works as expected)