Convert OciRuntimeBase.build_command from List -> Tuple

CHANGELOG.rst

@@ -3,6 +3,9 @@ Next Release
 
 Breaking changes:
 
+- change type of ``OciRuntimeBase.build_command`` from ``List[str]`` to
+  ``Tuple[str, ...]``
+
 
 Improvements and new features:
 

pytest_container/build.py

@@ -223,7 +223,7 @@ def run_build_step(
         with tempfile.TemporaryDirectory() as tmp_dir:
             iidfile = join(tmp_dir, str(uuid4()))
             cmd = (
-                runtime.build_command
+                [*runtime.build_command]
                 + (extra_build_args or [])
                 + [f"--iidfile={iidfile}"]
                 + (["--target", target] if target else [])

pytest_container/runtime.py

@@ -17,6 +17,7 @@
 from typing import Callable
 from typing import List
 from typing import Optional
+from typing import Tuple
 from typing import TYPE_CHECKING
 from typing import Union
 
@@ -182,7 +183,7 @@ def __gt__(self, other: Any) -> bool:
 @dataclass(frozen=True)
 class _OciRuntimeBase:
     #: command that builds the Dockerfile in the current working directory
-    build_command: List[str] = field(default_factory=list)
+    build_command: Tuple[str, ...] = field(default_factory=tuple)
     #: the "main" binary of this runtime, e.g. podman or docker
     runner_binary: str = ""
     _runtime_functional: bool = False
@@ -468,9 +469,9 @@ def _runtime_error_message() -> str:
     def __init__(self) -> None:
         super().__init__(
             build_command=(
-                ["buildah", "bud", "--layers", "--force-rm"]
+                ("buildah", "bud", "--layers", "--force-rm")
                 if self._buildah_functional
-                else ["podman", "build", "--layers", "--force-rm"]
+                else ("podman", "build", "--layers", "--force-rm")
             ),
             runner_binary="podman",
             _runtime_functional=self._runtime_functional,
@@ -571,7 +572,7 @@ def _runtime_error_message() -> str:
 
     def __init__(self) -> None:
         super().__init__(
-            build_command=["docker", "build", "--force-rm"],
+            build_command=("docker", "build", "--force-rm"),
             runner_binary="docker",
             _runtime_functional=self._runtime_functional,
         )