personal memory agent
conftest: fallback TMPDIR=/var/tmp for non-make pytest runs
make test exports TMPDIR=/var/tmp at the shell, but direct invocations
(.venv/bin/pytest, python -m pytest, uv run pytest) bypass the Makefile
and leak test dirs into /tmp. Add a module-level prelude in the root
conftest that sets TMPDIR and tempfile.tempdir to /var/tmp when TMPDIR
is unset, with a one-time stderr notice pointing at `make test` and a
visible degradation path when the target is not writable.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
+243
-1
+50
-1
conftest.py
+50
-1
conftest.py
···
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from __future__ import annotations
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11
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+
import os
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import subprocess
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import sys
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import tempfile
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from pathlib import Path
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_TMPDIR_FALLBACK_NOTICE: str | None = None
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def _apply_tmpdir_fallback() -> None:
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"""Route tmp dirs to /var/tmp when TMPDIR is not exported.
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make test sets TMPDIR=/var/tmp at the shell level (see Makefile). Direct
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pytest invocations (.venv/bin/pytest, python -m pytest, uv run pytest)
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bypass that. This prelude closes the gap by setting TMPDIR and
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tempfile.tempdir at module-import time, before pytest builds its
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tmp_path_factory.
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"""
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global _TMPDIR_FALLBACK_NOTICE
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if "TMPDIR" in os.environ:
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return
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# Test-only override so unwritable-target branch can be exercised
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# without chmod 000 /var/tmp.
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target = os.environ.get("_SOLSTONE_TMPDIR_FALLBACK_TARGET", "/var/tmp")
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if not (os.path.isdir(target) and os.access(target, os.W_OK)):
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if os.environ.get("_SOLSTONE_TMPDIR_FALLBACK_NOTIFIED") != "1":
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_TMPDIR_FALLBACK_NOTICE = (
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f"solstone: pytest invoked without TMPDIR export and fallback "
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f"target {target} is not writable; leaving TMPDIR unset.\n"
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)
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os.environ["_SOLSTONE_TMPDIR_FALLBACK_NOTIFIED"] = "1"
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return
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os.environ["TMPDIR"] = target
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tempfile.tempdir = target
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if os.environ.get("_SOLSTONE_TMPDIR_FALLBACK_NOTIFIED") != "1":
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_TMPDIR_FALLBACK_NOTICE = (
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f"solstone: pytest invoked without TMPDIR export; routing tmp dirs "
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f"to {target}. Prefer 'make test' to set TMPDIR at the shell level.\n"
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)
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os.environ["_SOLSTONE_TMPDIR_FALLBACK_NOTIFIED"] = "1"
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_apply_tmpdir_fallback()
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_FIXTURE_ROOT = "tests/fixtures"
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_BASELINE: set[tuple[str, str]] | None = None
···
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def pytest_sessionstart(session):
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global _BASELINE, _GIT_AVAILABLE
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global _BASELINE, _GIT_AVAILABLE, _TMPDIR_FALLBACK_NOTICE
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if _TMPDIR_FALLBACK_NOTICE is not None:
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sys.stderr.write(_TMPDIR_FALLBACK_NOTICE)
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_TMPDIR_FALLBACK_NOTICE = None
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repo_root = session.config.rootpath
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_BASELINE = _capture_status(repo_root)
+193
tests/test_tmpdir_fallback.py
+193
tests/test_tmpdir_fallback.py
···
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+
# SPDX-License-Identifier: AGPL-3.0-only
2
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# Copyright (c) 2026 sol pbc
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"""Canary tests for the root conftest TMPDIR fallback prelude."""
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5
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from __future__ import annotations
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+
7
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import os
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import subprocess
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import sys
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from pathlib import Path
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import pytest
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pytest_plugins = ["pytester"]
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_ROOT_CONFTEST = Path(__file__).resolve().parent.parent / "conftest.py"
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_NOTICE = (
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"solstone: pytest invoked without TMPDIR export; routing tmp dirs to "
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"/var/tmp. Prefer 'make test' to set TMPDIR at the shell level.\n"
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)
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def _install_root_conftest(pytester: pytest.Pytester) -> None:
24
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pytester.makepyfile(conftest=_ROOT_CONFTEST.read_text(encoding="utf-8"))
25
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26
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27
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def _run_nested(
28
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pytester: pytest.Pytester,
29
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env_overrides: dict[str, str | None] | None = None,
30
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) -> subprocess.CompletedProcess[str]:
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env = os.environ.copy()
32
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env.pop("TMPDIR", None)
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env.pop("_SOLSTONE_TMPDIR_FALLBACK_NOTIFIED", None)
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env.pop("_SOLSTONE_TMPDIR_FALLBACK_TARGET", None)
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if env_overrides:
36
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for key, value in env_overrides.items():
37
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if value is None:
38
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env.pop(key, None)
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else:
40
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env[key] = value
41
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return subprocess.run(
42
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[sys.executable, "-m", "pytest", "-q", "-p", "no:cacheprovider"],
43
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cwd=pytester.path,
44
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env=env,
45
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capture_output=True,
46
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text=True,
47
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check=False,
48
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)
49
+
50
+
51
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def test_prelude_redirects_to_var_tmp(pytester: pytest.Pytester) -> None:
52
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_install_root_conftest(pytester)
53
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pytester.makepyfile(
54
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test_tmpdir="""
55
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import os
56
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import tempfile
57
+
58
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def test_redirects_to_var_tmp():
59
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assert tempfile.gettempdir() == "/var/tmp"
60
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assert os.environ["TMPDIR"] == "/var/tmp"
61
+
"""
62
+
)
63
+
64
+
result = _run_nested(pytester)
65
+
66
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assert result.returncode == 0, result.stderr + result.stdout
67
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assert "1 passed" in result.stdout
68
+
69
+
70
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def test_notice_present_when_tmpdir_unset(pytester: pytest.Pytester) -> None:
71
+
_install_root_conftest(pytester)
72
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pytester.makepyfile(
73
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test_notice="""
74
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def test_noop():
75
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assert True
76
+
"""
77
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)
78
+
79
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result = _run_nested(pytester)
80
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combined = result.stderr + result.stdout
81
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82
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assert result.returncode == 0, combined
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assert _NOTICE in combined
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+
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def test_notice_absent_when_tmpdir_already_set(pytester: pytest.Pytester) -> None:
87
+
_install_root_conftest(pytester)
88
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pytester.makepyfile(
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test_notice="""
90
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import os
91
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import tempfile
92
+
93
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def test_uses_existing_tmpdir():
94
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assert tempfile.gettempdir() == "/tmp"
95
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assert os.environ["TMPDIR"] == "/tmp"
96
+
"""
97
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)
98
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99
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result = _run_nested(pytester, {"TMPDIR": "/tmp"})
100
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combined = result.stderr + result.stdout
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assert result.returncode == 0, combined
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assert "solstone: pytest invoked without TMPDIR" not in combined
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106
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def test_notice_single_fire_across_workers(pytester: pytest.Pytester) -> None:
107
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_install_root_conftest(pytester)
108
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pytester.makepyfile(
109
+
test_notice="""
110
+
def test_noop():
111
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assert True
112
+
"""
113
+
)
114
+
115
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first = _run_nested(pytester)
116
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second = _run_nested(pytester, {"_SOLSTONE_TMPDIR_FALLBACK_NOTIFIED": "1"})
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combined = first.stderr + first.stdout + second.stderr + second.stdout
118
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assert first.returncode == 0, combined
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assert second.returncode == 0, combined
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assert combined.count(_NOTICE) == 1
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123
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124
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def test_unwritable_target_degrades_visibly(
125
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pytester: pytest.Pytester, tmp_path: Path
126
+
) -> None:
127
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_install_root_conftest(pytester)
128
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pytester.makepyfile(
129
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test_notice="""
130
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import os
131
+
132
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def test_tmpdir_stays_unset():
133
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assert os.environ.get("TMPDIR") is None
134
+
"""
135
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)
136
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blocked = tmp_path / "blocked"
137
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blocked.mkdir()
138
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os.chmod(blocked, 0)
139
+
140
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try:
141
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result = _run_nested(
142
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pytester, {"_SOLSTONE_TMPDIR_FALLBACK_TARGET": str(blocked)}
143
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)
144
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finally:
145
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os.chmod(blocked, 0o700)
146
+
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combined = result.stderr + result.stdout
148
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notice = (
149
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"solstone: pytest invoked without TMPDIR export and fallback target "
150
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f"{blocked} is not writable; leaving TMPDIR unset.\n"
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)
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+
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assert result.returncode == 0, combined
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assert notice in combined
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assert "routing tmp dirs to" not in combined
156
+
157
+
158
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def test_subprocess_pytest_lands_in_var_tmp(pytester: pytest.Pytester) -> None:
159
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_install_root_conftest(pytester)
160
+
test_path = pytester.makepyfile(
161
+
test_subprocess="""
162
+
import os
163
+
import tempfile
164
+
165
+
def test_redirects_in_fresh_subprocess():
166
+
assert tempfile.gettempdir() == "/var/tmp"
167
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assert os.environ["TMPDIR"] == "/var/tmp"
168
+
"""
169
+
)
170
+
env = os.environ.copy()
171
+
env.pop("TMPDIR", None)
172
+
env.pop("_SOLSTONE_TMPDIR_FALLBACK_NOTIFIED", None)
173
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env.pop("_SOLSTONE_TMPDIR_FALLBACK_TARGET", None)
174
+
175
+
result = subprocess.run(
176
+
[
177
+
sys.executable,
178
+
"-m",
179
+
"pytest",
180
+
"-q",
181
+
"-p",
182
+
"no:cacheprovider",
183
+
str(test_path),
184
+
],
185
+
cwd=pytester.path,
186
+
env=env,
187
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capture_output=True,
188
+
text=True,
189
+
check=False,
190
+
)
191
+
192
+
assert result.returncode == 0, result.stderr + result.stdout
193
+
assert "1 passed" in result.stdout