Add --no-config option

piptools/scripts/compile.py

@@ -319,6 +319,13 @@ def _determine_linesep(
     is_eager=True,
     callback=override_defaults_from_config_file,
 )
+@click.option(
+    "--no-config",
+    is_flag=True,
+    default=False,
+    help="Do not read any config file.",
+    is_eager=True,
+)
 def cli(
     ctx: click.Context,
     verbose: int,
@@ -358,6 +365,7 @@ def cli(
     emit_options: bool,
     unsafe_package: tuple[str, ...],
     config: Path | None,
+    no_config: bool,
 ) -> None:
     """
     Compiles requirements.txt from requirements.in, pyproject.toml, setup.cfg,

piptools/scripts/sync.py

@@ -103,6 +103,13 @@
     is_eager=True,
     callback=override_defaults_from_config_file,
 )
+@click.option(
+    "--no-config",
+    is_flag=True,
+    default=False,
+    help="Do not read any config file.",
+    is_eager=True,
+)
 def cli(
     ask: bool,
     dry_run: bool,
@@ -121,6 +128,7 @@ def cli(
     src_files: tuple[str, ...],
     pip_args: str | None,
     config: Path | None,
+    no_config: bool,
 ) -> None:
     """Synchronize virtual environment with requirements.txt."""
     log.verbosity = verbose - quiet

piptools/utils.py

@@ -54,6 +54,7 @@
     "--verbose",
     "--cache-dir",
     "--no-reuse-hashes",
+    "--no-config",
 }
 
 
@@ -548,6 +549,9 @@ def override_defaults_from_config_file(
     file. Those files are searched for in the same directory as the requirements
     input file, or the current working directory if requirements come via stdin.
     """
+    if ctx.params.get("no_config"):
+        return None
+
     if value is None:
         config_file = select_config_file(ctx.params.get("src_files", ()))
         if config_file is None:

tests/test_cli_compile.py

@@ -2973,3 +2973,17 @@ def test_config_option(pip_conf, runner, tmp_path, make_config_file):
 
     assert out.exit_code == 0
     assert "Dry-run, so nothing updated" in out.stderr
+
+
+def test_no_config_option(pip_conf, runner, tmp_path, make_config_file):
+    config_file = make_config_file("dry-run", True)
+
+    req_in = tmp_path / "requirements.in"
+    req_in.touch()
+
+    out = runner.invoke(
+        cli, [req_in.as_posix(), "--no-config", "--config", config_file.as_posix()]
+    )
+
+    assert out.exit_code == 0
+    assert "Dry-run, so nothing updated" not in out.stderr

tests/test_cli_sync.py

@@ -385,3 +385,16 @@ def test_config_option(run, runner, make_config_file):
 
     assert out.exit_code == 1
     assert "Would install:" in out.stdout
+
+
+@mock.patch("piptools.sync.run")
+def test_no_config_option(run, runner, make_config_file):
+    config_file = make_config_file("dry-run", True)
+
+    with open(sync.DEFAULT_REQUIREMENTS_FILE, "w") as reqs_txt:
+        reqs_txt.write("six==1.10.0")
+
+    out = runner.invoke(cli, ["--no-config", "--config", config_file.as_posix()])
+
+    assert out.exit_code == 0
+    assert "Would install:" not in out.stdout