Exported requirements.txt contains spurious messages if lock file does not exist

• Poetry version: 1.3.2
• Python version: 3.10.6
• OS version and name: Ubuntu 22.04.1
• pyproject.toml: just create it with poetry new poetry-demo:

[tool.poetry]
name = "poetry-demo"
version = "0.1.0"
description = ""
authors = ["Patrick Decat"]
readme = "README.md"
packages = [{include = "poetry_demo"}]

[tool.poetry.dependencies]
python = "^3.10"


[build-system]
requires = ["poetry-core"]
build-backend = "poetry.core.masonry.api"

• I am on the latest stable Poetry version, installed using a recommended method.
• I have searched the issues of this repo and believe that this is not a duplicate.
• I have consulted the FAQ and blog for any relevant entries or release notes.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option) and have included the output below.

Issue

When lock file does not exist, poetry export writes some messages to standard output:

# poetry --version
Poetry (version 1.3.2)

# poetry new poetry-demo
Created package poetry_demo in poetry-demo

# cd poetry-demo/

# poetry export -f requirements.txt > requirements.txt
The lock file does not exist. Locking.
Creating virtualenv poetry-demo in /home/patrick/workspaces/tests/poetry/poetry-demo/.venv

# cat requirements.txt
Updating dependencies
Resolving dependencies...

Writing lock file

Related:

• https://github.com/python-poetry/poetry/issues/4109
• https://github.com/python-poetry/poetry/issues/4110

Start with the poetry export -f requirements.txt command path and reproduce the issue using a new project without a lock file. Trace where locking and dependency-resolution messages are written during export; done means the generated requirements.txt contains only requirements output, not status messages.