• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: Ubuntu 20.04.4
• Poetry version: 1.2.0b2
• Link of a Gist with the contents of your pyproject.toml file:

[tool.poetry]
name = "meow"
version = "0.1.0"
description = ""
authors = [""]
build = "build.py"

[tool.poetry.dependencies]
python = "^3.9"
SoundFile = "0.10.*"
crcmod = "^1.7"
librosa = ">=0.8.0"
numba = "^0.56.0"
protobuf = "3.14.0"
tensorboard = "^2.10.0"
torchaudio = {version = "=0.12.1+cu113", source="torch"}
torch = {version = "=1.12.1+cu113", source="torch"}

[[tool.poetry.source]]
name = "torch"
url = "https://download.pytorch.org/whl/cu113"
secondary = true

[tool.poetry.dev-dependencies]

[build-system]
requires = ["poetry-core>=1.0.0", "setuptools>=40.6.0", "wheel", "numpy", "pybind11"]
build-backend = "poetry.core.masonry.api"

Issue

Running poetry build with the above pyproject.toml does the right thing:

Preparing build environment with build-system requirements poetry-core>=1.0.0, setuptools>=40.6.0, wheel, numpy, pybind11
[...snip...]

Running poetry install fails because it attempts to build the project without installing build-system.requires packages.

I would have expected the install command to create an isolated environment, install the build requirements and perform the build in that isolated environment, and then install the produced artifact in my current environment.