Add NETRC to the default_pass_env list (#3410)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Bernát Gábor <gaborjbernat@gmail.com>

docs/changelog/3410.feature.rst

@@ -0,0 +1 @@
+Add ``NETRC`` to the list of environment variables always passed through.

docs/config.rst

@@ -530,6 +530,11 @@ Base options
             - ✅
             - ✅
             - ✅
+        *   - NETRC
+            - ✅
+            - ✅
+            - ✅
+
 
 
    More environment variable-related information

src/tox/tox_env/api.py

@@ -220,6 +220,7 @@ def _default_pass_env(self) -> list[str]:  # noqa: PLR6301
             "HOME",  # needed for `os.path.expanduser()` on non-Windows systems
             "FORCE_COLOR",  # force color output
             "NO_COLOR",  # disable color output
+            "NETRC",  # used by pip and netrc modules
         ]
         if sys.stdout.isatty():  # if we're on a interactive shell pass on the TERM
             env.append("TERM")

tests/session/cmd/test_show_config.py

@@ -126,7 +126,7 @@ def test_pass_env_config_default(tox_project: ToxProjectCreator, stdout_is_atty:
         + ["CPPFLAGS", "CURL_CA_BUNDLE", "CXX", "FORCE_COLOR", "HOME", "LANG"]
         + ["LANGUAGE", "LDFLAGS", "LD_LIBRARY_PATH"]
         + (["MSYSTEM"] if is_win else [])
-        + ["NO_COLOR"]
+        + ["NETRC", "NO_COLOR"]
         + (["NUMBER_OF_PROCESSORS", "PATHEXT"] if is_win else [])
         + ["PIP_*", "PKG_CONFIG", "PKG_CONFIG_PATH", "PKG_CONFIG_SYSROOT_DIR"]
         + (["PROCESSOR_ARCHITECTURE"] if is_win else [])