[build-system]
requires = ["poetry>=0.12"]
build-backend = "poetry.masonry.api"

[tool.poetry]
name = "pkgconfig"
version = "1.5.1"
license = "MIT"
description = "Interface Python with pkg-config"
authors = ["Matthias Vogelgesang <matthias.vogelgesang@gmail.com>"]
readme = "README.rst"
homepage = "https://github.com/matze/pkgconfig"
classifiers = [
    "Development Status :: 5 - Production/Stable",
    "Intended Audience :: Developers",
    "Operating System :: OS Independent",
    "Topic :: Software Development :: Build Tools",
]

[tool.poetry.dependencies]
python = "~2.7 || ^3.3"

[tool.poetry.dev-dependencies]
pytest = "^3.8.2"

[build-system]
requires = ["poetry_core>=1.0.0"]
build-backend = "poetry.core.masonry.api"

[tool.poetry]
name = "pkgconfig"
version = "1.5.1"
license = "MIT"
description = "Interface Python with pkg-config"
authors = ["Matthias Vogelgesang <matthias.vogelgesang@gmail.com>"]
readme = "README.rst"
homepage = "https://github.com/matze/pkgconfig"
classifiers = [
    "Development Status :: 5 - Production/Stable",
    "Intended Audience :: Developers",
    "Operating System :: OS Independent",
    "Topic :: Software Development :: Build Tools",
]

[tool.poetry.dependencies]
python = "~2.7 || ^3.3"

[tool.poetry.dev-dependencies]
pytest = "^3.8.2"

Use `poetry_core` as build backend
Use `poetry_core` as build backend

According to https://python-poetry.org/docs/pyproject/#poetry-and-pep-517

> If your `pyproject.toml` file still references `poetry` directly as a build backend,
> you should update it to reference poetry_core instead.