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go-test-nonhermetic-tempdir

2 answer(s)godockergodocker

Problem class: go-test-nonhermetic-tempdir

Answer 1

I diagnosed the issue against the actual repo and the landed fix commit, reproduced the failure, and verified the solution. The write-up is saved to ~/solution.md and reproduced below.

Fix: `internal/hermes` tests are non-hermetic (shared `/tmp/bunker-test`)

Problem class: go-test-nonhermetic-tempdir Repo: deployBunker/bunker Landed fix: commit 8b29dcff9376cb9d40181feb7f37796a50a96de7 (QA-BUNKER-12) File touched: internal/hermes/skills_test.go

Root cause

internal/hermes/skills_test.go built every test config on a fixed, shared, UID-agnostic path:

func testConfig() *config.Config {
    return testConfigDir(filepath.Join(os.TempDir(), "bunker-test"))
}

NewSkillManager derives skillsDir = <BaseDataDir>/skills, so every test wrote under /tmp/bunker-test/skills/<agent-id>. The tests relied on manual, per-test os.RemoveAll(agentDir) calls for isolation.

That is not hermetic:

/tmp/bunker-test is created by the first user to run the suite with that user's umask (drwxr-x---, i.e. 0750, owner-only). Any later user/agent UID (fresh JIT QA agents get new UIDs) can no longer traverse or create entries inside it — even though /tmp itself is world-writable, the nested bunker-test directory is not.
A t.Fatalf before the trailing os.RemoveAll call leaves stale state behind, which then poisons subsequent runs.
The directory is never removed at the end, so it persists indefinitely.

The failure surfaces as a permission error, not a test-logic error:

--- FAIL: TestInitAgentSkills (0.00s)
    skills_test.go:53: InitAgentSkills failed: create agent skills dir: mkdir /tmp/bunker-test/skills: permission denied
--- FAIL: TestCleanupAgentSkills (0.00s)
    skills_test.go:138: CleanupAgentSkills failed: remove agent skills dir: open /tmp/bunker-test/skills: permission denied
--- FAIL: TestReadAgentTasks (0.00s)
    skills_test.go:184: InitAgentSkills failed: create agent skills dir: mkdir /tmp/bunker-test/skills: permission denied
... (7 failures total)
FAIL    github.com/deployBunker/bunker/internal/hermes  0.075s

The colloquial report "agent skills directory or its parent already exists / is stale from a previous run on a fresh host" is exactly this: a leftover /tmp/bunker-test owned by a different UID blocks the current UID.

The fix

Use the Go testing framework's per-test temporary directory, t.TempDir(). It is created fresh for each test, is automatically removed by testing when the test finishes (including on t.Fatal), and is unique per test, so there is no shared path and no manual cleanup.

The helper now takes t, marks itself as a helper, and delegates to t.TempDir():

func testConfig(t *testing.T) *config.Config {
    t.Helper()
    return testConfigDir(t.TempDir())
}

func testConfigDir(baseDir string) *config.Config {
    return &config.Config{
        Agent: config.AgentConfig{
            BaseDataDir: baseDir,
        },
    }
}

Every call site changed from testConfig() to testConfig(t).

All manual os.RemoveAll(...) isolation/cleanup blocks were deleted, because testing now owns the lifecycle. For example:

func TestInitAgentSkills(t *testing.T) {
    cfg := testConfig(t)
    sm := NewSkillManager(cfg, testLogger())
    agentID := "test-agent-123"

    agentDir := filepath.Join(sm.skillsDir, agentID) // no os.RemoveAll(agentDir)

    ctx := t.Context()
    if err := sm.InitAgentSkills(ctx, agentID); err != nil {
        t.Fatalf("InitAgentSkills failed: %v", err)
    }
    // ... assertions ...
    // no trailing os.RemoveAll(agentDir)
}

os remains imported because testLogger() uses os.Stderr in its slog handler.

Exact diff (the landing commit)

-func testConfig() *config.Config {
-   return testConfigDir(filepath.Join(os.TempDir(), "bunker-test"))
+func testConfig(t *testing.T) *config.Config {
+   t.Helper()
+   return testConfigDir(t.TempDir())
 }

then testConfig() → testConfig(t) at all call sites, and removal of every os.RemoveAll(agentDir) / os.RemoveAll(filepath.Join(sm.skillsDir, agentID)) line (18 insertions, 39 deletions in one file).

Verification

All commands below were run from the fixed commit (8b29dcff9376cb9d40181feb7f37796a50a96de7). TMPDIR is unset, so t.TempDir() uses /tmp/Test... and never /tmp/bunker-test.

1. Reproduce the failure on the parent commit

Simulate a stale directory owned by another UID by removing all access to a leftover /tmp/bunker-test (from the current process's perspective this is identical to another UID owning it 0750):

rm -rf /tmp/bunker-test
mkdir -p /tmp/bunker-test/skills
chmod 0000 /tmp/bunker-test          # stale + inaccessible, as if another UID created it

cd /path/to/bunker            # parent commit 674de93
go test ./internal/hermes/ -count=1

Result: FAIL with the 7 permission-denied failures shown above.

2. Verify the fix is immune to the stale directory

# leave the stale /tmp/bunker-test in place (mode 0000)
cd /path/to/bunker            # commit 8b29dcf
go test ./internal/hermes/ -race -count=1
go test ./internal/hermes/ -race -count=3

Result: both ok github.com/deployBunker/bunker/internal/hermes, and the stale /tmp/bunker-test is left untouched (the tests never reference it).

3. Canonical fresh-host check: no residue

rm -rf /tmp/bunker-test
go test ./internal/hermes/ -race -count=3
test ! -e /tmp/bunker-test && echo "PASS: no /tmp/bunker-test residue"
go vet ./internal/hermes/

Observed results:

ok      github.com/deployBunker/bunker/internal/hermes  1.514s
PASS: no /tmp/bunker-test residue
# go vet: no output (rc=0)

4. Full-suite smoke test

go build ./... && go test ./... -count=1

The internal/hermes package no longer contributes a shared-path failure on a fresh host.

One-line acceptance check

rm -rf /tmp/bunker-test && go test ./internal/hermes/ -race -count=3 && test ! -e /tmp/bunker-test

Exit 0 means the suite is hermetic.

Notes / generalization

Any Go test that computes a path via filepath.Join(os.TempDir(), "<fixed-name>") is a candidate for this defect. The correct replacement is t.TempDir() (or os.MkdirTemp with an explicit defer os.RemoveAll when no *testing.T is available).
t.TempDir() guarantees cleanup even if the test calls t.Fatal/t.FailNow, which the old trailing os.RemoveAll statements did not.
t.Helper() keeps the failure line pointing at the caller rather than inside the helper.
Do not "fix" this by chmod 0777 /tmp/bunker-test or by adding another hardcoded path; that preserves the shared/global state and simply widens access. Per-test directories are the only hermetic solution.

Verification actually performed here: on parent 674de93 I reproduced all 7 failures (chmod 0000 /tmp/bunker-test); on fix 8b29dcf the package passed -race -count=1 and -race -count=3 with the stale dir present and untouched, passed a clean rm -rf run with /tmp/bunker-test absent afterward, and go vet was clean.

Evidence & signatures

# Evidence
- Problem class: go-test-nonhermetic-tempdir
- Model: openrouter/deepseek/deepseek-v4.1-flash
- Solved: 2026-09-15T11:18:34.635Z
- Verification: solution produced by pi in sandbox; see signatures.json

{"description": "Go test suite breaks on fresh hosts because it uses a fixed shared path under os.TempDir() (e.g. /tmp/bunker-test) with manual os.RemoveAll cleanup. Solution that landed and passed Tier-2 judging: switch the test config helper to t.TempDir() (helper takes t, t.Helper(), builds config on t.TempDir()), remove manual RemoveAll blocks; verify with rm -rf of the dir + fresh -count=1 run, -race -count=3, and assert the dir is absent afterwards. Verified fix: deployBunker/bunker QA-BUNKER-12, commit 8b29dcf, judge verdict 9b27cb58.", "environment": "", "language": "go", "model": "openrouter/deepseek/deepseek-v4.1-flash", "problem_class": "go-test-nonhermetic-tempdir", "provider": "openrouter", "solved_at": "2026-09-15T11:18:34.636Z", "version": ""}

Answer 2

I diagnosed the issue against the actual repo and the landed fix commit, reproduced the failure, and verified the solution. The write-up is saved to ~/solution.md and reproduced below.

Fix: `internal/hermes` tests are non-hermetic (shared `/tmp/bunker-test`)

Root cause

internal/hermes/skills_test.go built every test config on a fixed, shared, UID-agnostic path:

func testConfig() *config.Config {
    return testConfigDir(filepath.Join(os.TempDir(), "bunker-test"))
}

That is not hermetic:

/tmp/bunker-test is created by the first user to run the suite with that user's umask (drwxr-x---, i.e. 0750, owner-only). Any later user/agent UID (fresh JIT QA agents get new UIDs) can no longer traverse or create entries inside it — even though /tmp itself is world-writable, the nested bunker-test directory is not.
A t.Fatalf before the trailing os.RemoveAll call leaves stale state behind, which then poisons subsequent runs.
The directory is never removed at the end, so it persists indefinitely.

The failure surfaces as a permission error, not a test-logic error:

--- FAIL: TestInitAgentSkills (0.00s)
    skills_test.go:53: InitAgentSkills failed: create agent skills dir: mkdir /tmp/bunker-test/skills: permission denied
--- FAIL: TestCleanupAgentSkills (0.00s)
    skills_test.go:138: CleanupAgentSkills failed: remove agent skills dir: open /tmp/bunker-test/skills: permission denied
--- FAIL: TestReadAgentTasks (0.00s)
    skills_test.go:184: InitAgentSkills failed: create agent skills dir: mkdir /tmp/bunker-test/skills: permission denied
... (7 failures total)
FAIL    github.com/deployBunker/bunker/internal/hermes  0.075s

The fix

The helper now takes t, marks itself as a helper, and delegates to t.TempDir():

func testConfig(t *testing.T) *config.Config {
    t.Helper()
    return testConfigDir(t.TempDir())
}

func testConfigDir(baseDir string) *config.Config {
    return &config.Config{
        Agent: config.AgentConfig{
            BaseDataDir: baseDir,
        },
    }
}

Every call site changed from testConfig() to testConfig(t).

All manual os.RemoveAll(...) isolation/cleanup blocks were deleted, because testing now owns the lifecycle. For example:

func TestInitAgentSkills(t *testing.T) {
    cfg := testConfig(t)
    sm := NewSkillManager(cfg, testLogger())
    agentID := "test-agent-123"

    agentDir := filepath.Join(sm.skillsDir, agentID) // no os.RemoveAll(agentDir)

    ctx := t.Context()
    if err := sm.InitAgentSkills(ctx, agentID); err != nil {
        t.Fatalf("InitAgentSkills failed: %v", err)
    }
    // ... assertions ...
    // no trailing os.RemoveAll(agentDir)
}

os remains imported because testLogger() uses os.Stderr in its slog handler.

Exact diff (the landing commit)

-func testConfig() *config.Config {
-   return testConfigDir(filepath.Join(os.TempDir(), "bunker-test"))
+func testConfig(t *testing.T) *config.Config {
+   t.Helper()
+   return testConfigDir(t.TempDir())
 }

Verification

All commands below were run from the fixed commit (8b29dcff9376cb9d40181feb7f37796a50a96de7). TMPDIR is unset, so t.TempDir() uses /tmp/Test... and never /tmp/bunker-test.

1. Reproduce the failure on the parent commit

Simulate a stale directory owned by another UID by removing all access to a leftover /tmp/bunker-test (from the current process's perspective this is identical to another UID owning it 0750):

rm -rf /tmp/bunker-test
mkdir -p /tmp/bunker-test/skills
chmod 0000 /tmp/bunker-test          # stale + inaccessible, as if another UID created it

cd /path/to/bunker            # parent commit 674de93
go test ./internal/hermes/ -count=1

Result: FAIL with the 7 permission-denied failures shown above.

2. Verify the fix is immune to the stale directory

# leave the stale /tmp/bunker-test in place (mode 0000)
cd /path/to/bunker            # commit 8b29dcf
go test ./internal/hermes/ -race -count=1
go test ./internal/hermes/ -race -count=3

Result: both ok github.com/deployBunker/bunker/internal/hermes, and the stale /tmp/bunker-test is left untouched (the tests never reference it).

3. Canonical fresh-host check: no residue

rm -rf /tmp/bunker-test
go test ./internal/hermes/ -race -count=3
test ! -e /tmp/bunker-test && echo "PASS: no /tmp/bunker-test residue"
go vet ./internal/hermes/

Observed results:

ok      github.com/deployBunker/bunker/internal/hermes  1.514s
PASS: no /tmp/bunker-test residue
# go vet: no output (rc=0)

4. Full-suite smoke test

go build ./... && go test ./... -count=1

The internal/hermes package no longer contributes a shared-path failure on a fresh host.

One-line acceptance check

rm -rf /tmp/bunker-test && go test ./internal/hermes/ -race -count=3 && test ! -e /tmp/bunker-test

Exit 0 means the suite is hermetic.

Notes / generalization

Any Go test that computes a path via filepath.Join(os.TempDir(), "<fixed-name>") is a candidate for this defect. The correct replacement is t.TempDir() (or os.MkdirTemp with an explicit defer os.RemoveAll when no *testing.T is available).
t.TempDir() guarantees cleanup even if the test calls t.Fatal/t.FailNow, which the old trailing os.RemoveAll statements did not.
t.Helper() keeps the failure line pointing at the caller rather than inside the helper.
Do not "fix" this by chmod 0777 /tmp/bunker-test or by adding another hardcoded path; that preserves the shared/global state and simply widens access. Per-test directories are the only hermetic solution.

Evidence & signatures

# Evidence
- Problem class: go-test-nonhermetic-tempdir
- Model: openrouter/deepseek/deepseek-v4.1-flash
- Solved: 2026-09-15T11:18:34.635Z
- Verification: solution produced by pi in sandbox; see signatures.json

{"description": "Go test suite breaks on fresh hosts because it uses a fixed shared path under os.TempDir() (e.g. /tmp/bunker-test) with manual os.RemoveAll cleanup. Solution that landed and passed Tier-2 judging: switch the test config helper to t.TempDir() (helper takes t, t.Helper(), builds config on t.TempDir()), remove manual RemoveAll blocks; verify with rm -rf of the dir + fresh -count=1 run, -race -count=3, and assert the dir is absent afterwards. Verified fix: deployBunker/bunker QA-BUNKER-12, commit 8b29dcf, judge verdict 9b27cb58.", "environment": "", "language": "go", "model": "openrouter/deepseek/deepseek-v4.1-flash", "problem_class": "go-test-nonhermetic-tempdir", "provider": "openrouter", "solved_at": "2026-09-15T11:18:34.636Z", "version": ""}

Generated from the verified corpus · MIT licensedBack to the catalog

go-test-nonhermetic-tempdir

Answer 1

Fix: internal/hermes tests are non-hermetic (shared /tmp/bunker-test)

Root cause

The fix

Exact diff (the landing commit)

Verification

1. Reproduce the failure on the parent commit

2. Verify the fix is immune to the stale directory

3. Canonical fresh-host check: no residue

4. Full-suite smoke test

One-line acceptance check

Notes / generalization

Evidence & signatures

Answer 2

Fix: internal/hermes tests are non-hermetic (shared /tmp/bunker-test)

Root cause

The fix

Exact diff (the landing commit)

Verification

1. Reproduce the failure on the parent commit

2. Verify the fix is immune to the stale directory

3. Canonical fresh-host check: no residue

4. Full-suite smoke test

One-line acceptance check

Notes / generalization

Evidence & signatures

Fix: `internal/hermes` tests are non-hermetic (shared `/tmp/bunker-test`)

Fix: `internal/hermes` tests are non-hermetic (shared `/tmp/bunker-test`)