fix: harden diagnostics memory parsing

Author: wolone

pilot/core/diagnostics.py

@@ -215,14 +215,31 @@ def _pid_alive(self, path: Path) -> bool:
             return False
 
     def _linux_memory(self) -> dict[str, int]:
-        path = Path("/proc/meminfo")
+        path = self._meminfo_path()
         if not path.exists():
             return {}
-        fields = {}
-        for line in path.read_text().splitlines():
+        fields: dict[str, int] = {}
+        try:
+            lines = path.read_text().splitlines()
+        except OSError:
+            return {}
+        for line in lines:
+            if ":" not in line:
+                continue
             key, value = line.split(":", 1)
-            fields[key] = int(value.strip().split()[0])
-        return {"available": fields.get("MemAvailable", 0)}
+            parts = value.strip().split()
+            if not parts:
+                continue
+            try:
+                fields[key] = int(parts[0])
+            except ValueError:
+                continue
+        if "MemAvailable" not in fields:
+            return {}
+        return {"available": fields["MemAvailable"]}
+
+    def _meminfo_path(self) -> Path:
+        return Path("/proc/meminfo")
 
     def _tcp_open(self, host: str, port: int) -> bool:
         try:

tests/test_diagnostics.py

@@ -130,6 +130,24 @@ def test_diagnostics_cpu_load_warns_under_pressure(tmp_path: Path, monkeypatch)
     assert check.status == "warn"
 
 
+def test_diagnostics_memory_parser_ignores_malformed_lines(tmp_path: Path, monkeypatch) -> None:
+    bench = make_initialized_bench(tmp_path)
+    meminfo = tmp_path / "meminfo"
+    meminfo.write_text("broken\nMemTotal:\nMemFree: nope kB\nMemAvailable: 2048 kB\n")
+    monkeypatch.setattr(DiagnosticRunner, "_meminfo_path", lambda self: meminfo)
+
+    assert DiagnosticRunner(bench)._linux_memory() == {"available": 2048}
+
+
+def test_diagnostics_memory_parser_skips_without_available_memory(tmp_path: Path, monkeypatch) -> None:
+    bench = make_initialized_bench(tmp_path)
+    meminfo = tmp_path / "meminfo"
+    meminfo.write_text("MemTotal: 4096 kB\n")
+    monkeypatch.setattr(DiagnosticRunner, "_meminfo_path", lambda self: meminfo)
+
+    assert DiagnosticRunner(bench)._memory_check().status == "skip"
+
+
 def test_diagnostic_report_json(tmp_path: Path) -> None:
     bench = make_initialized_bench(tmp_path)
     check = DiagnosticRunner(bench)._path_check("bench", "bench.toml", bench.path / "bench.toml", "")