feat: nix support

- Provide a dev shell. - Provide a nix package. - Provide a nix flake. - Development environment based on direnv. - Docs. - Configure Gitpod to use direnv and nix. - Configure Cachix out of the box, and document how to use it. - Add direnv and nix to CI. - Satisfy some linters that came from Precommix, even when Precommix was later discarded. - Mark some tests as impure. - Run only pure tests when building Copier with Nix. - Add poetry loader to direnv. - Update contribution guide.
2025-05-05 15:32:54 +00:00 · 2023-01-18 09:40:08 +00:00 · 2023-01-18 09:40:08 +00:00 · 67cc4ffde3
commit 67cc4ffde3
parent dae31980a3
33 changed files with 1254 additions and 953 deletions
--- a/.editorconfig
+++ b/.editorconfig
@ -1,12 +1,16 @@
-# Defaults for all kinds of source code
-[*]
-charset = utf-8
-end_of_line = lf
-indent_size = 4
-indent_style = space
-insert_final_newline = true
-trim_trailing_whitespace = true
+root = true

-# Specific language overrides
-[*.{yml,yaml,json}]
+[*]
+indent_style = space
+indent_size = 4
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.py]
+# For isort
+profile = black
+
+[*.{code-snippets,code-workspace,json,lock,nix,tf,yaml,yml}{,.jinja}]
 indent_size = 2
--- a/.envrc
+++ b/.envrc
@ -0,0 +1,19 @@
+# SEE https://github.com/direnv/direnv/wiki/Python#poetry
+layout_poetry() {
+    VIRTUAL_ENV=$(poetry env info --path 2>/dev/null ; true)
+
+    if [[ -z $VIRTUAL_ENV || ! -d $VIRTUAL_ENV ]]; then
+        log_status "No virtual environment exists. Executing \`poetry install\` to create one."
+        poetry install --with dev,docs
+        VIRTUAL_ENV=$(poetry env info --path)
+    fi
+
+    PATH_add "$VIRTUAL_ENV/bin"
+    export POETRY_ACTIVE=1
+    export VIRTUAL_ENV
+}
+
+use flake . \
+    --extra-substituters 'https://copier.cachix.org https://devenv.cachix.org' \
+    --extra-trusted-public-keys 'copier.cachix.org-1:sVkdQyyNXrgc53qXPCH9zuS91zpt5eBYcg7JQSmTBG4= devenv.cachix.org-1:w1cLUi8dv3hnoSPGAuibQv+f9TZLr6cv/Hm9XgU50cw='
+layout_poetry
--- a/.flake8
+++ b/.flake8
@ -1,4 +1,6 @@
 [flake8]
-extend-ignore = W503,E203,E501,D100,D101,D102,D103,D104,D105,D107,SIM117
-max-complexity = 20
+ignore = E203, E501, W503, B950
 max-line-length = 88
+select = C,E,F,W,B
+per-file-ignores=
+    __init__.py:F401
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@ -68,7 +68,7 @@ jobs:
      - name: Install dependencies
        run: |
          python -m pip install poetry poetry-dynamic-versioning
-          poetry install --with docs -v
+          poetry install --with dev,docs -v
      - name: Run pytest
        run: poetry run poe test --cov=./ --cov-report=xml -ra .
      - name: Upload coverage to Codecov
@ -84,9 +84,55 @@ jobs:
          name: copier
          token: ${{ secrets.CODECOV_TOKEN }}

+  flake-check:
+    strategy:
+      fail-fast: false
+      matrix:
+        os:
+          - macos-latest
+          - ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v3
+
+      # Install Nix and set up Cachix
+      - uses: cachix/install-nix-action@v17
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
+      - uses: cachix/cachix-action@v11
+        with:
+          authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+          extraPullNames: devenv
+          name: copier
+          pushFilter: (-source$|nixpkgs\.tar\.gz$)
+
+      # Cache for poetry venv when using direnv
+      - uses: actions/cache@v3
+        with:
+          path: |
+            .cache
+            .devenv
+            .direnv
+            .venv
+          key:
+            direnv|${{ runner.os }}|${{ hashFiles('pyproject.toml', '*.lock', '*.nix')
+            }}
+
+      # Check direnv works as expected
+      - uses: JRMurr/direnv-nix-action@v2
+        with:
+          install-nix: "false"
+          cache-store: "false"
+      - run: copier --version
+
+      # Run nix checks
+      - run: nix flake check -L
+
  publish:
    if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')
-    needs: build
+    needs:
+      - build
+      - flake-check
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
--- a/.gitignore
+++ b/.gitignore
@ -58,3 +58,9 @@ htmlcov/

 # macOS
 .DS_Store
+
+# Nix
+/.devenv
+/.direnv
+/.pre-commit-config.yaml
+/result*
--- a/.gitpod.dockerfile
+++ b/.gitpod.dockerfile
@ -1,8 +0,0 @@
-FROM gitpod/workspace-full
-USER gitpod
-ENV PIP_USER=no POETRY_VIRTUALENVS_IN_PROJECT=true
-RUN pip3 install \
-    commitizen \
-    poethepoet \
-    poetry \
-    poetry-dynamic-versioning
--- a/.gitpod.yml
+++ b/.gitpod.yml
@ -1,3 +1,10 @@
+github:
+  prebuilds:
+    addBadge: true
+    addCheck: prevent-merge-on-error
+    master: true
+    pullRequests: true
+
 vscode:
  extensions:
    - bpruitt-goddard.mermaid-markdown-syntax-highlighting
@ -5,15 +12,10 @@ vscode:
    - esbenp.prettier-vscode
    - ms-python.python

-image:
-  file: .gitpod.dockerfile
-
 ports:
  # Mkdocs local server; start it with `poe docs`
  - port: 8000
    onOpen: notify

 tasks:
-  - init:
-      export PIP_USER=no && poetry install -E docs && poetry run pre-commit install -t
-      pre-commit -t commit-msg && poetry run pre-commit install-hooks
+  - init: direnv allow
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@ -1,99 +0,0 @@
-default_language_version:
-  python: python3
-
-default_stages:
-  - commit
-
-repos:
-  # checking our hooks themselves
-  - repo: meta
-    hooks:
-      - id: check-hooks-apply
-      - id: check-useless-excludes
-
-  # hooks running from local virtual environment
-  - repo: local
-    hooks:
-      - id: autoflake
-        name: autoflake
-        entry: poetry run autoflake
-        language: system
-        types: [python]
-        args: ["-i", "--remove-all-unused-imports", "--ignore-init-module-imports"]
-      - id: black
-        name: black
-        entry: poetry run black
-        language: system
-        types: [python]
-        require_serial: true
-      - id: flake8
-        name: flake8
-        entry: poetry run flake8
-        language: system
-        types: [python]
-        require_serial: true
-      - id: poetry_check
-        description: Check the integrity of pyproject.toml
-        name: poetry_check
-        entry: poetry check
-        language: system
-        pass_filenames: false
-        require_serial: true
-      - id: poetry-lock-check
-        name: poetry-lock-check
-        entry: poetry lock
-        args: ["--check"]
-        language: system
-        pass_filenames: false
-      - id: isort
-        name: isort
-        entry: poetry run isort
-        require_serial: true
-        language: system
-        types_or: [cython, pyi, python]
-        args: ["--filter-files"]
-      - id: commitizen
-        name: commitizen
-        entry: poetry run cz check
-        args: [--allow-abort, --commit-msg-file]
-        language: system
-        stages: [commit-msg]
-
-  - repo: https://github.com/asottile/pyupgrade
-    rev: v3.2.1
-    hooks:
-      - id: pyupgrade
-        args: [--py37-plus]
-
-  # prettier to format our many yaml files
-  - repo: https://github.com/pre-commit/mirrors-prettier
-    rev: v2.7.1
-    hooks:
-      - id: prettier
-        exclude: |
-          (?x)
-          # Those files have wrong syntax and would fail
-          ^tests/demo_invalid/copier.yml|tests/demo_transclude_invalid(_multi)?/demo/copier.yml$
-          # HACK https://github.com/prettier/prettier/issues/9430
-          |^tests/demo
-
-  # miscellaneous hooks
-  - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.3.0
-    hooks:
-      - id: check-added-large-files
-      - id: check-ast
-      - id: check-case-conflict
-      - id: check-docstring-first
-      - id: check-executables-have-shebangs
-      - id: check-merge-conflict
-      - id: check-toml
-      - id: debug-statements
-      - id: detect-private-key
-      - id: end-of-file-fixer
-        exclude: \.noeof\. # Some tests require no EOF
-      - id: fix-encoding-pragma
-        args: ["--remove"]
-      - id: mixed-line-ending
-        args: ["--fix=lf"]
-      - id: trailing-whitespace
--- a/.prettierrc.yml
+++ b/.prettierrc.yml
@ -1,5 +1,2 @@
-# Defaults for all prettier-supported languages
-bracketSpacing: false
-endOfLine: lf
 printWidth: 88
 proseWrap: always
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@ -47,14 +47,21 @@ Feel free to discuss with our community through

 ## Dev Environment Setup

+The recommended way is:
+
+1. Click on
+   [![Gitpod ready-to-code](https://img.shields.io/badge/Gitpod-ready--to--code-blue?logo=gitpod)](https://gitpod.io/#https://github.com/copier-org/copier)
+1. Wait until the terminal that pops up is ready.
+1. Accept the direnv and nix pop-ups that appear.
+
+For local or more complex setups, continue reading.
+
 We use some tools as part of our development workflow which you'll need to install into
 your host environment:

-   [Poetry](https://python-poetry.org/) v1.2+ for packaging and dependency management
-
-Or you can use
-[![Gitpod ready-to-code](https://img.shields.io/badge/Gitpod-ready--to--code-blue?logo=gitpod)](https://gitpod.io/#https://github.com/copier-org/copier)
-to start hacking with one click!
+-   [Nix](https://nixos.org/download.html) to provide a reproducible development
+    environment.
+-   [Direnv](https://direnv.net/) to load that environment automatically in your shell.

 ## Get Started!

@ -68,22 +75,18 @@ Ready to contribute? Here's how to set up the project for local development.
    cd copier
    ```

-1.  Use Poetry to set up a development environment:
+1.  Use Direnv to set up a development environment:

    ```shell
-    # Tell Poetry to create the virtualenv in the project directory
-    poetry config virtualenvs.in-project true --local
-
-    # Create a virtualenv with all dependencies from pyproject.toml
-    poetry install --with docs
-
-    # Install development helper tools
-    poetry run pre-commit install -t pre-commit -t commit-msg
-
-    # Create a new shell with the virtualenv activated
-    poetry shell
+    # Let direnv do its magic
+    direnv allow
    ```

+    Direnv will take some time to load for the 1st time. It will download all
+    development dependencies, including [Poetry](https://python-poetry.org/), and it
+    will use it to create a virtualenv and install Copier with all its development
+    dependencies too.
+
 1.  Create a branch for local development:

    ```shell
@ -99,9 +102,6 @@ Ready to contribute? Here's how to set up the project for local development.
    poe lint
    ```

-    To have multiple Python versions on the same machine for running `tox`, I recommend
-    using [pyenv](https://github.com/pyenv/pyenv) (_do not_ confuse it with `pipenv`,).
-
 1.  Commit your changes and push your branch to GitHub:

    ```shell
@ -118,6 +118,7 @@ Before you submit a pull request, check that it meets these guidelines:

 1.  The pull request has code, it should include tests.
 1.  Check that all checks pass on GitHub CI.
+1.  If something significant changed, modify docs.

 ## Tips

@ -126,3 +127,13 @@ To run a subset of tests:
 ```shell
 poe test tests/the-tests-file.py
 ```
+
+### Nix binary cache
+
+Our direnv configuration is configured to use binary caches by default.
+
+However, to add our binary caches permanently:
+
+```shell
+nix-shell -p cachix --run 'cachix use copier && cachix use devenv'
+```
--- a/README.md
+++ b/README.md
@ -25,6 +25,7 @@ A library and CLI app for rendering project templates.
 1. Install Git 2.27 or newer.
 1. To use as a CLI app: `pipx install copier`
 1. To use as a library: `pip install copier` or `conda install -c conda-forge copier`
+1. To use with 100% reproducibility: `nix profile install github:copier-org/copier`

 ## Quick start

--- a/copier/main.py
+++ b/copier/main.py
@ -1,4 +1,7 @@
+"""Copier CLI entrypoint."""
 from copier.cli import CopierApp

+# HACK https://github.com/nix-community/poetry2nix/issues/504
+copier_app_run = CopierApp.run
 if __name__ == "__main__":
-    CopierApp.run()
+    copier_app_run()
--- a/copier/cli.py
+++ b/copier/cli.py
@ -1,4 +1,3 @@
-#!/usr/bin/env python
 """
 Command line entrypoint. This module declares the Copier CLI applications.

@ -83,6 +82,7 @@ class CopierApp(cli.Application):

    Attributes:
        answers_file: Set [answers_file][] option.
+        conflict: Set [conflict][] option.
        exclude: Set [exclude][] option.
        vcs_ref: Set [vcs_ref][] option.
        pretend: Set [pretend][] option.
@ -356,6 +356,3 @@ if __doc__:
        CopierApp.run(["copier", "--help-all"], exit=False)
    help_io.seek(0)
    __doc__ += f"\n\nCLI help generated from `copier --help-all`:\n\n```\n{help_io.read()}\n```"
-
-if __name__ == "__main__":
-    CopierApp.run()
--- a/copier/main.py
+++ b/copier/main.py
@ -77,7 +77,9 @@ class Worker:

    Example:
        ```python
-        with Worker(src_path="https://github.com/copier-org/autopretty.git", "output") as worker:
+        with Worker(
+            src_path="https://github.com/copier-org/autopretty.git", "output"
+        ) as worker:
            worker.run_copy()
        ```

@ -171,9 +173,11 @@ class Worker:
    conflict: str = "rej"

    def __enter__(self):
+        """Allow using worker as a context manager."""
        return self

    def __exit__(self, type, value, traceback):
+        """Clean up garbage files after worker usage ends."""
        if value is not None:
            # exception was raised from code inside context manager:
            # try to clean up, ignoring any exception, then re-raise
@ -302,7 +306,6 @@ class Worker:
        """Determine if a file or directory can be rendered.

        Args:
-
            dst_relpath:
                Relative path to destination.
            is_dir:
@ -473,7 +476,6 @@ class Worker:
        """Render one file.

        Args:
-
            src_abspath:
                The absolute path to the file that will be rendered.
        """
@ -824,7 +826,7 @@ class Worker:
 def run_copy(
    src_path: str,
    dst_path: StrOrPath = ".",
-    data: AnyByStrDict = None,
+    data: Optional[AnyByStrDict] = None,
    **kwargs,
 ) -> Worker:
    """Copy a template to a destination, from zero.
@ -842,7 +844,7 @@ def run_copy(

 def run_update(
    dst_path: StrOrPath = ".",
-    data: AnyByStrDict = None,
+    data: Optional[AnyByStrDict] = None,
    **kwargs,
 ) -> Worker:
    """Update a subproject, from its template.
@ -861,7 +863,7 @@ def run_update(
 def run_auto(
    src_path: OptStr = None,
    dst_path: StrOrPath = ".",
-    data: AnyByStrDict = None,
+    data: Optional[AnyByStrDict] = None,
    **kwargs,
 ) -> Worker:
    """Generate or update a subproject.
--- a/copier/subproject.py
+++ b/copier/subproject.py
@ -39,7 +39,7 @@ class Subproject:
    answers_relpath: Path = Path(".copier-answers.yml")

    def is_dirty(self) -> bool:
-        """Indicates if the local template root is dirty.
+        """Indicate if the local template root is dirty.

        Only applicable for VCS-tracked templates.
        """
@ -50,7 +50,7 @@ class Subproject:

    @property
    def _raw_answers(self) -> AnyByStrDict:
-        """The last answers, loaded raw as yaml."""
+        """Get last answers, loaded raw as yaml."""
        try:
            return yaml.safe_load(
                (self.local_abspath / self.answers_relpath).read_text()
--- a/copier/template.py
+++ b/copier/template.py
@ -360,7 +360,7 @@ class Template:

    @cached_property
    def min_copier_version(self) -> Optional[Version]:
-        """Gets minimal copier version for the template and validates it.
+        """Get minimal copier version for the template and validates it.

        See [min_copier_version][].
        """
--- a/copier/tools.py
+++ b/copier/tools.py
@ -18,16 +18,18 @@ from pydantic import StrictBool

 from .types import IntSeq

-try:
-    from importlib.metadata import version
-except ImportError:
-    # Python < 3.8
+# TODO Remove condition when dropping python 3.8 support
+if sys.version_info < (3, 8):
    from importlib_metadata import version
+else:
+    from importlib.metadata import version

 colorama.init()


 class Style:
+    """Common color styles."""
+
    OK: IntSeq = [colorama.Fore.GREEN, colorama.Style.BRIGHT]
    WARNING: IntSeq = [colorama.Fore.YELLOW, colorama.Style.BRIGHT]
    IGNORE: IntSeq = [colorama.Fore.CYAN]
@ -63,6 +65,7 @@ def printf(
    quiet: Union[bool, StrictBool] = False,
    file_: TextIO = sys.stdout,
 ) -> Optional[str]:
+    """Print string with common format."""
    if quiet:
        return None  # HACK: Satisfy MyPy
    _msg = str(msg)
@ -78,6 +81,7 @@ def printf(
 def printf_exception(
    e: Exception, action: str, msg: str = "", indent: int = 0, quiet: bool = False
 ) -> None:
+    """Print exception with common format."""
    if not quiet:
        print("", file=sys.stderr)
        printf(action, msg=msg, style=Style.DANGER, indent=indent, file_=sys.stderr)
@ -114,6 +118,7 @@ def cast_str_to_bool(value: Any) -> bool:


 def copy_file(src_path: Path, dst_path: Path, follow_symlinks: bool = True) -> None:
+    """Copy one file to another place."""
    shutil.copy2(src_path, dst_path, follow_symlinks=follow_symlinks)


@ -166,6 +171,7 @@ class TemporaryDirectory(tempfile.TemporaryDirectory):
        warnings.warn(warn_message, ResourceWarning)

    def cleanup(self):
+        """Remove directory safely."""
        if self._finalizer.detach():
            self._robust_cleanup(self.name)

--- a/copier/types.py
+++ b/copier/types.py
@ -40,11 +40,14 @@ Env = Mapping[str, str]


 class AllowArbitraryTypes:
+    """Allow any type for this class."""
+
    arbitrary_types_allowed = True


 # Validators
 def path_is_absolute(value: Path) -> Path:
+    """Require absolute paths in an argument."""
    if not value.is_absolute():
        from .errors import PathNotAbsoluteError

@ -53,6 +56,7 @@ def path_is_absolute(value: Path) -> Path:


 def path_is_relative(value: Path) -> Path:
+    """Require relative paths in an argument."""
    if value.is_absolute():
        from .errors import PathNotRelativeError

@ -67,12 +71,16 @@ if TYPE_CHECKING:
 else:

    class AbsolutePath(Path):
+        """Require absolute paths in an argument."""
+
        @classmethod
        def __get_validators__(cls) -> "CallableGenerator":
            yield path_validator
            yield path_is_absolute

    class RelativePath(Path):
+        """Require relative paths in an argument."""
+
        @classmethod
        def __get_validators__(cls) -> "CallableGenerator":
            yield path_validator
--- a/copier/user_data.py
+++ b/copier/user_data.py
@ -135,6 +135,7 @@ class AnswersMap:
        )

    def old_commit(self) -> OptStr:
+        """Commit when the project was updated from this template the last time."""
        return self.last.get("_commit")


--- a/copier/vcs.py
+++ b/copier/vcs.py
@ -56,7 +56,7 @@ def is_git_bundle(path: Path) -> bool:


 def get_repo(url: str) -> OptStr:
-    """Transforms `url` into a git-parseable origin URL.
+    """Transform `url` into a git-parseable origin URL.

    Args:
        url:
@ -133,7 +133,6 @@ def clone(url: str, ref: OptStr = None) -> str:
        ref:
            Reference to checkout. For Git repos, defaults to `HEAD`.
    """
-
    location = mkdtemp(prefix=f"{__name__}.clone.")
    _clone = git["clone", "--no-checkout", url, location]
    # Faster clones if possible
--- a/default.nix
+++ b/default.nix
@ -0,0 +1,14 @@
+(
+  import
+  (
+    let
+      lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+    in
+      fetchTarball {
+        url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+        sha256 = lock.nodes.flake-compat.locked.narHash;
+      }
+  )
+  {src = ./.;}
+)
+.defaultNix
--- a/devtasks.py
+++ b/devtasks.py
@ -1,3 +1,4 @@
+"""Development helper tasks."""
 import os
 import shutil
 from pathlib import Path
@ -5,9 +6,7 @@ from subprocess import check_call


 def clean():
-    """
-    Clean build, test or other process artefacts from the project workspace
-    """
+    """Clean build, test or other process artifacts from the project workspace."""
    build_artefacts = (
        "build/",
        "dist/",
@ -33,7 +32,7 @@ def clean():


 def dev_setup():
-    """Setup a development environment."""
+    """Set up a development environment."""
    # Gitpod sets PIP_USER=yes, which breaks poetry
    env = dict(os.environ, PIP_USER="no")
    check_call(["poetry", "install", "--with", "docs"], env=env)
--- a/flake.lock
+++ b/flake.lock
@ -0,0 +1,302 @@
+{
+  "nodes": {
+    "devenv": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "nix": "nix",
+        "nixpkgs": "nixpkgs",
+        "pre-commit-hooks": "pre-commit-hooks"
+      },
+      "locked": {
+        "lastModified": 1671716968,
+        "narHash": "sha256-LThNtwAXH/0KVMgyTFBwl93ktuWpWTZhCh6NBlydBbQ=",
+        "owner": "cachix",
+        "repo": "devenv",
+        "rev": "ba6818f4c39fd95aebdb6dc441401f2b60484652",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "ref": "v0.5",
+        "repo": "devenv",
+        "type": "github"
+      }
+    },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1668681692,
+        "narHash": "sha256-Ht91NGdewz8IQLtWZ9LCeNXMSXHUss+9COoqu6JLmXU=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "009399224d5e398d03b22badca40a37ac85412a1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "flake-compat_2": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1668681692,
+        "narHash": "sha256-Ht91NGdewz8IQLtWZ9LCeNXMSXHUss+9COoqu6JLmXU=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "009399224d5e398d03b22badca40a37ac85412a1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1667395993,
+        "narHash": "sha256-nuEHfE/LcWyuSWnS8t12N1wc105Qtau+/OdUAjtQ0rA=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "5aed5285a952e0b949eb3ba02c12fa4fcfef535f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_2": {
+      "locked": {
+        "lastModified": 1667395993,
+        "narHash": "sha256-nuEHfE/LcWyuSWnS8t12N1wc105Qtau+/OdUAjtQ0rA=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "5aed5285a952e0b949eb3ba02c12fa4fcfef535f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_3": {
+      "locked": {
+        "lastModified": 1667395993,
+        "narHash": "sha256-nuEHfE/LcWyuSWnS8t12N1wc105Qtau+/OdUAjtQ0rA=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "5aed5285a952e0b949eb3ba02c12fa4fcfef535f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "gitignore": {
+      "inputs": {
+        "nixpkgs": [
+          "devenv",
+          "pre-commit-hooks",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1660459072,
+        "narHash": "sha256-8DFJjXG8zqoONA1vXtgeKXy68KdJL5UaXR8NtVMUbx8=",
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "rev": "a20de23b925fd8264fd7fad6454652e142fd7f73",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "type": "github"
+      }
+    },
+    "lowdown-src": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1633514407,
+        "narHash": "sha256-Dw32tiMjdK9t3ETl5fzGrutQTzh2rufgZV4A/BbxuD4=",
+        "owner": "kristapsdz",
+        "repo": "lowdown",
+        "rev": "d2c2b44ff6c27b936ec27358a2653caaef8f73b8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "kristapsdz",
+        "repo": "lowdown",
+        "type": "github"
+      }
+    },
+    "nix": {
+      "inputs": {
+        "lowdown-src": "lowdown-src",
+        "nixpkgs": [
+          "devenv",
+          "nixpkgs"
+        ],
+        "nixpkgs-regression": "nixpkgs-regression"
+      },
+      "locked": {
+        "lastModified": 1671638174,
+        "narHash": "sha256-FeEmVix8l/HglWtRgeHOfjqEm2etvp+MLYd1C/raq3Y=",
+        "owner": "domenkozar",
+        "repo": "nix",
+        "rev": "51b770e985f9e1b84fb5e03a983ef1e19f18c3e9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "domenkozar",
+        "ref": "relaxed-flakes",
+        "repo": "nix",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1671458120,
+        "narHash": "sha256-2+k/OONN4OF21TeoNjKB5sXVZv6Zvm/uEyQIW9OYCg8=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e37ef84b478fa8da0ced96522adfd956fde9047a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-regression": {
+      "locked": {
+        "lastModified": 1643052045,
+        "narHash": "sha256-uGJ0VXIhWKGXxkeNnq4TvV3CIOkUJ3PAoLZ3HMzNVMw=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "215d4d0fd80ca5163643b03a33fde804a29cc1e2",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "215d4d0fd80ca5163643b03a33fde804a29cc1e2",
+        "type": "github"
+      }
+    },
+    "nixpkgs-stable": {
+      "locked": {
+        "lastModified": 1671271954,
+        "narHash": "sha256-cSvu+bnvN08sOlTBWbBrKaBHQZq8mvk8bgpt0ZJ2Snc=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "d513b448cc2a6da2c8803e3c197c9fc7e67b19e3",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-22.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1673800717,
+        "narHash": "sha256-SFHraUqLSu5cC6IxTprex/nTsI81ZQAtDvlBvGDWfnA=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "2f9fd351ec37f5d479556cd48be4ca340da59b8f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-22.11",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_3": {
+      "locked": {
+        "lastModified": 1673940514,
+        "narHash": "sha256-jM1c0V6EBqea9fLMyrfIrB4gbnXrW0gVswYjGdu0JiE=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "29a7c9631b7405dcf480138f417682af8a4069c7",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "poetry2nix": {
+      "inputs": {
+        "flake-utils": "flake-utils_3",
+        "nixpkgs": "nixpkgs_3"
+      },
+      "locked": {
+        "lastModified": 1673926875,
+        "narHash": "sha256-QOsT76Al0Igpo0u5vtQJuDSOxrocX3sTD523pLPEklc=",
+        "owner": "nix-community",
+        "repo": "poetry2nix",
+        "rev": "a5c454a834cd290dd4d33102ab8b4aa37d850e65",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "poetry2nix",
+        "type": "github"
+      }
+    },
+    "pre-commit-hooks": {
+      "inputs": {
+        "flake-compat": [
+          "devenv",
+          "flake-compat"
+        ],
+        "flake-utils": "flake-utils",
+        "gitignore": "gitignore",
+        "nixpkgs": [
+          "devenv",
+          "nixpkgs"
+        ],
+        "nixpkgs-stable": "nixpkgs-stable"
+      },
+      "locked": {
+        "lastModified": 1671452357,
+        "narHash": "sha256-HqzXiQEegpRQ4VEl9pEPgHSIxhJrNJ27HfN1wOc7w2E=",
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "rev": "200790e9c77064c53eaf95805b013d96615ecc27",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "devenv": "devenv",
+        "flake-compat": "flake-compat_2",
+        "flake-utils": "flake-utils_2",
+        "nixpkgs": "nixpkgs_2",
+        "poetry2nix": "poetry2nix"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
--- a/flake.nix
+++ b/flake.nix
@ -0,0 +1,110 @@
+{
+  inputs = {
+    devenv.url = "github:cachix/devenv/v0.5";
+    flake-compat = {
+      url = github:edolstra/flake-compat;
+      flake = false;
+    };
+    flake-utils.url = github:numtide/flake-utils;
+    nixpkgs.url = github:NixOS/nixpkgs/nixos-22.11;
+    poetry2nix.url = github:nix-community/poetry2nix;
+  };
+
+  outputs = inputs:
+    with inputs;
+      flake-utils.lib.eachDefaultSystem (system: let
+        pkgs = import nixpkgs {
+          inherit system;
+          overlays = [poetry2nix.overlay];
+        };
+        lastRelease = (pkgs.lib.importTOML ./pyproject.toml).tool.commitizen.version;
+        version = "${lastRelease}.dev${self.sourceInfo.lastModifiedDate}+nix-git-${self.sourceInfo.shortRev or "dirty"}";
+
+        # Builders
+        copierApp = pkgs.poetry2nix.mkPoetryApplication {
+          inherit version;
+          name = "copier-${version}";
+          POETRY_DYNAMIC_VERSIONING_BYPASS = version;
+          projectDir = ./.;
+          overrides = pkgs.poetry2nix.overrides.withDefaults (final: prev: {
+            pydantic = prev.pydantic.overrideAttrs (old: {
+              buildInputs = old.buildInputs ++ [pkgs.libxcrypt];
+            });
+          });
+
+          # Test configuration
+          checkInputs = [pkgs.git];
+          pythonImportsCheck = ["copier"];
+          doCheck = true;
+          installCheckPhase = ''
+            patchShebangs tests
+            env \
+              GIT_AUTHOR_EMAIL=copier@example.com \
+              GIT_AUTHOR_NAME=copier \
+              GIT_COMMITTER_EMAIL=copier@example.com \
+              GIT_COMMITTER_NAME=copier \
+              PATH=$out/bin:$PATH \
+              POETRY_VIRTUALENVS_PATH=$NIX_BUILD_TOP/virtualenvs \
+              PYTHONOPTIMIZE= \
+              pytest --color=yes -m 'not impure'
+          '';
+        };
+        copierModule = pkgs.python3.pkgs.toPythonModule copierApp;
+      in rec {
+        devShells.default = devenv.lib.mkShell {
+          inherit inputs pkgs;
+          modules = [
+            {
+              packages = with pkgs; [
+                # Essential dev tools
+                (pkgs.python3.withPackages (ps:
+                  with ps; [
+                    poetry
+                    poetry-dynamic-versioning
+                  ]))
+
+                # IDE integration tools
+                alejandra
+                black
+                commitizen
+                isort
+                mypy
+                nodePackages.prettier
+              ];
+              difftastic.enable = true;
+              pre-commit.hooks = {
+                alejandra.enable = true;
+                black.enable = true;
+                commitizen.enable = true;
+                editorconfig-checker.enable = true;
+                editorconfig-checker.excludes = [
+                  "\.md$"
+                  "\.noeof\."
+                  "\.bundle$"
+                ];
+                flake8.enable = true;
+                isort.enable = true;
+                prettier.enable = true;
+                prettier.excludes = [
+                  # Those files have wrong syntax and would fail
+                  "^tests/demo_invalid/copier.yml$"
+                  "^tests/demo_transclude_invalid(_multi)?/demo/copier.yml$"
+                  # HACK https://github.com/prettier/prettier/issues/9430
+                  "^tests/demo"
+                ];
+              };
+            }
+          ];
+        };
+        packages.default = copierModule;
+        apps =
+          builtins.mapAttrs
+          (name: value: flake-utils.lib.mkApp {drv = value;})
+          packages;
+        checks =
+          packages
+          // {
+            devenv-ci = devShells.default.ci;
+          };
+      });
+}
--- a/img/copier-logotype.svg
+++ b/img/copier-logotype.svg
@ -1,4 +1,4 @@
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+<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
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    inkscape:export-filename="/Users/jps/Projects/copier/copier-logo.png"
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+            <cc:Work rdf:about="">
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-        <dc:type
-           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
-        <dc:title></dc:title>
+                <dc:type rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+                <dc:title />
            </cc:Work>
        </rdf:RDF>
    </metadata>
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        </g>
        <text
            id="text4613"
            y="48.697594"
            x="100.25542"
            style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:31.1556778px;line-height:1.25;font-family:Rockwell;-inkscape-font-specification:'Rockwell, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;letter-spacing:0px;word-spacing:0px;writing-mode:lr-tb;text-anchor:start;fill:#000000;fill-opacity:1;stroke:none;stroke-width:0.77889198"
-       xml:space="preserve"><tspan
+            xml:space="preserve"
+        >
+            <tspan
                style="font-style:normal;font-variant:normal;font-weight:normal;font-stretch:normal;font-size:31.1556778px;font-family:Rockwell;-inkscape-font-specification:'Rockwell, Normal';font-variant-ligatures:normal;font-variant-caps:normal;font-variant-numeric:normal;font-feature-settings:normal;text-align:start;writing-mode:lr-tb;text-anchor:start;stroke-width:0.77889198"
                y="48.697594"
                x="100.25542"
                id="tspan4611"
-         sodipodi:role="line">Copier</tspan></text>
+                sodipodi:role="line"
+            >
+                Copier
+            </tspan>
+        </text>
    </g>
 </svg>
--- a/poetry.lock
+++ b/poetry.lock
--- a/pyproject.toml
+++ b/pyproject.toml
@ -20,7 +20,7 @@ repository = "https://github.com/copier-org/copier"
 readme = "README.md"

 [tool.poetry.scripts]
-copier = "copier.cli:CopierApp.run"
+copier = "copier.__main__:copier_app_run"

 [tool.poetry.urls]
 "Bug Tracker" = "https://github.com/copier-org/copier/issues"
@ -44,25 +44,20 @@ pyyaml-include = ">=1.2"
 questionary = ">=1.8.1"
 typing-extensions = { version = ">=3.7.4,<5.0.0", python = "<3.8" }

+[tool.poetry.group.dev]
+optional = true
+
 [tool.poetry.group.dev.dependencies]
-autoflake = ">=1.4"
-black = ">=22.1"
-commitizen = ">=2.32.2"
-flake8 = ">=4.0.1"
-flake8-bugbear = ">=22.1.11"
-flake8-comprehensions = ">=3.8.0"
-flake8-debugger = ">=4.0.0"
-flake8-simplify = ">=0.19.3"
-isort = ">=5.10.1"
 mypy = ">=0.931"
 pexpect = ">=4.8.0"
 poethepoet = ">=0.12.3"
 pre-commit = ">=2.17.0"
-pytest = ">=7.0.1"
+pytest = ">=7.2.0"
 pytest-cov = ">=3.0.0"
 pytest-xdist = ">=2.5.0"
 types-backports = ">=0.1.3"
 types-pyyaml = ">=6.0.4"
+types-psutil = "*"

 [tool.poetry.group.docs]
 optional = true
@ -117,8 +112,15 @@ ignore_missing_imports = true
 plugins = ["pydantic.mypy"]
 warn_no_return = false

+[tool.pydocstyle]
+match_dir = "^copier"
+add_ignore = ["D105", "D107"]
+
 [tool.pytest.ini_options]
 addopts = "-n auto -ra"
+markers = [
+    "impure: needs network or is not 100% reproducible"
+]

 [tool.commitizen]
 annotated_tag = true
@ -128,5 +130,5 @@ update_changelog_on_bump = true
 version = "7.1.0a0"

 [build-system]
-requires = ["poetry_core>=1.0.0", "poetry-dynamic-versioning"]
+requires = ["poetry-core>=1.0.0", "poetry-dynamic-versioning"]
 build-backend = "poetry_dynamic_versioning.backend"
--- a/shell.nix
+++ b/shell.nix
@ -0,0 +1,12 @@
+{lock ? builtins.fromJSON (builtins.readFile ./flake.lock)}:
+(
+  import
+  (
+    fetchTarball {
+      url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
+      sha256 = lock.nodes.flake-compat.locked.narHash;
+    }
+  )
+  {src = ./.;}
+)
+.shellNix
--- a/tests/test_copy.py
+++ b/tests/test_copy.py
@ -134,6 +134,7 @@ def test_copy(tmp_path):
    assert os.path.exists(tmp_path / "py3_folder" / "thing.py")


+@pytest.mark.impure
 def test_copy_repo(tmp_path):
    copier.copy(
        "gh:copier-org/copier.git",
--- a/tests/test_tools.py
+++ b/tests/test_tools.py
@ -1,24 +1,12 @@
-import platform
 from pathlib import Path
 from stat import S_IREAD

-import pytest
 from plumbum.cmd import git
 from poethepoet.app import PoeThePoet

 from copier.tools import TemporaryDirectory


-@pytest.mark.skipif(
-    condition=platform.system() == "Windows",
-    reason="Windows does weird things with line endings.",
-)
-def test_lint():
-    """Ensure source code formatting"""
-    result = PoeThePoet(Path("."))(["lint", "--show-diff-on-failure", "--color=always"])
-    assert result == 0
-
-
 def test_types():
    """Ensure source code static typing."""
    result = PoeThePoet(Path("."))(["types"])
@ -38,5 +26,5 @@ def test_temporary_directory_with_readonly_files_deletion():
 def test_temporary_directory_with_git_repo_deletion():
    """Ensure temporary directories containing git repositories are properly deleted, whatever the OS."""
    with TemporaryDirectory() as tmp_dir:
-        git("clone", "--depth=1", ".", Path(tmp_dir) / "repo")
+        git("init")
    assert not Path(tmp_dir).exists()
--- a/tests/test_updatediff.py
+++ b/tests/test_updatediff.py
@ -17,6 +17,7 @@ from copier.types import RelativePath
 from .helpers import BRACKET_ENVOPS_JSON, SUFFIX_TMPL, build_file_tree


+@pytest.mark.impure
 def test_updatediff(tmp_path_factory):
    src, dst = map(tmp_path_factory.mktemp, ("src", "dst"))
    # Prepare repo bundle
@ -285,6 +286,7 @@ def test_updatediff(tmp_path_factory):
@pytest.mark.xfail(
    condition=platform.system() == "Windows", reason="Git broken on Windows?"
 )
+@pytest.mark.impure
 def test_commit_hooks_respected(tmp_path_factory):
    """Commit hooks are taken into account when producing the update diff."""
    # Prepare source template v1
@ -476,7 +478,7 @@ def test_skip_update(tmp_path_factory):
        git("commit", "-m1")
        git("tag", "1.0.0")
    run_copy(str(src), dst, defaults=True, overwrite=True)
-    skip_me: Path = dst / "skip_me"
+    skip_me = dst / "skip_me"
    answers_file = dst / ".copier-answers.yml"
    answers = yaml.safe_load(answers_file.read_text())
    assert skip_me.read_text() == "1"
--- a/tests/test_vcs.py
+++ b/tests/test_vcs.py
@ -3,6 +3,7 @@ import shutil
 from os.path import exists, join
 from pathlib import Path

+import pytest
 from plumbum import local
 from plumbum.cmd import git

@ -60,6 +61,7 @@ def test_get_repo():
    )


+@pytest.mark.impure
 def test_clone():
    tmp = vcs.clone("https://github.com/copier-org/copier.git")
    assert tmp
@ -67,6 +69,7 @@ def test_clone():
    shutil.rmtree(tmp, ignore_errors=True)


+@pytest.mark.impure
 def test_removes_temporary_clone(tmp_path):
    src_path = "https://github.com/copier-org/autopretty.git"
    with Worker(src_path=src_path, dst_path=tmp_path, defaults=True) as worker:
@ -75,6 +78,7 @@ def test_removes_temporary_clone(tmp_path):
    assert not temp_clone.exists()


+@pytest.mark.impure
 def test_dont_remove_local_clone(tmp_path):
    src_path = vcs.clone("https://github.com/copier-org/autopretty.git")
    with Worker(src_path=src_path, dst_path=tmp_path, defaults=True) as worker:
@ -82,6 +86,7 @@ def test_dont_remove_local_clone(tmp_path):
    assert exists(src_path)


+@pytest.mark.impure
 def test_update_using_local_source_path_with_tilde(tmp_path):
    # first, get a local repository clone
    src_path = vcs.clone("https://github.com/copier-org/autopretty.git")