fix: say when Windows does not answer under WSL

install.ps1

@@ -16,7 +16,7 @@
     # and Invoke-WebRequest throws on a cut transfer before the hash is read:
     # the site's build rewrites this line there (scripts/sitebootstrap.py).
     $mismatchAdvice = "The download was most likely cut short: try again. Within minutes of an update of this project the two files can come from caches of different ages. Waiting five minutes settles that."
-    $defaultInstallSha256 = "1096705acbaa531b7e05458cc58b393426b7e1577d0db62bd2cd29e1c8257ca3"
+    $defaultInstallSha256 = "450cee7625f098d5796452b02ab9c8bffdeaaef89180d2254bbe07ce354bc359"
     $maximumInstallerBytes = 2MB
     $installerExit = 0
     $installer = if ($PSScriptRoot) { Join-Path $PSScriptRoot "install.py" } else { $null }

install.py

@@ -1200,7 +1200,9 @@ def _parse_os_release() -> dict[str, str]:
 # Set under WSL: a Windows path read from a config or a rule names a drive
 # that Linux sees under /mnt (drvfs). C:\\RetroBat\\bios was used as a relative
 # path and nothing Windows-side was ever found from WSL.
-_WSL = {"active": False, "root": "/mnt"}
+# unasked: why Windows could not be asked for its folders, said once by
+# detection.
+_WSL = {"active": False, "root": "/mnt", "unasked": ""}
 _WINDOWS_VARIABLES = ("USERPROFILE", "APPDATA", "LOCALAPPDATA", "ProgramFiles", "ProgramFiles(x86)")
 
 
@@ -1255,13 +1257,27 @@ def _enter_wsl() -> None:
                 capture_output=True, text=True, timeout=10, stdin=subprocess.DEVNULL,
                 cwd="/mnt/c" if Path("/mnt/c").is_dir() else None,
             )
-        except (OSError, subprocess.SubprocessError):
+        except (OSError, subprocess.SubprocessError) as exc:
+            # The others would wait as long: detection is told the Windows
+            # side was not searched, never that nothing is there.
+            _windows_unasked("cmd.exe", exc)
             return
         value = result.stdout.strip()
         if value and not value.startswith("%"):
             os.environ[variable] = str(_host_path(value))
 
 
+def _windows_unasked(tool: str, exc: Exception) -> None:
+    """Keep why a Windows program run from WSL gave no answer: an interop
+    slow to start or turned off hid every Windows setup, and the run said
+    none was installed."""
+    if isinstance(exc, subprocess.TimeoutExpired):
+        why = f"{tool} did not answer in {exc.timeout:g} s"
+    else:
+        why = f"{tool} could not run: {getattr(exc, 'strerror', None) or exc}"
+    _WSL["unasked"] = _WSL["unasked"] or why
+
+
 def _expand_retroarch_path(value: str, app_dir: Path, home: Path | None = None) -> Path:
     """Expand the notations RetroArch writes into its config values.
 
@@ -2521,6 +2537,9 @@ def refused_words(folder: Path, why: str, shown: str = "") -> str:
     """The line said for a folder detection could not look in. shown is
     the folder as the screen writes it (~/.config/EmuDeck), the full path
     by default."""
+    if _WSL["active"] and why == _WSL["unasked"] and folder == Path(_WSL["root"]):
+        return (f"Could not look for setups on the Windows side: {why}. "
+                "Run it again once Windows answers, or name the BIOS folder with --dest.")
     if folder in _DETECTION_UNREADABLE:
         return (f"Could not look for setups: {shown or folder} could not be read ({why}). "
                 "A failing card or a link that loops gives this: check it, or name the "
@@ -2555,6 +2574,22 @@ def _note_refused(path: Path, exc: OSError) -> None:
     print(f"  {screen_text(words)}", file=sys.stderr)
 
 
+def _note_windows_unasked() -> None:
+    """Say once, as a folder detection could not look in, that Windows did
+    not answer: its drives are then searched without its folders."""
+    why = _WSL["unasked"]
+    if (not why or not getattr(_SETUP_SEARCH, "active", False)
+            or getattr(_SETUP_SEARCH, "quiet", False)):
+        return
+    refused = (Path(_WSL["root"]), why)
+    if refused in _DETECTION_REFUSED:
+        return
+    _DETECTION_REFUSED.append(refused)
+    words = refused_words(*refused)
+    EVENTS.emit("unsearched", folder=str(refused[0]), reason=why, message=words)
+    print(f"  {screen_text(words)}", file=sys.stderr)
+
+
 def _detection_guarded(detect: Callable[..., list]) -> Callable[..., list]:
     """Detection whose probes treat a folder this user cannot open as
     absent, and say so once.
@@ -2694,7 +2729,9 @@ def _read_registry(key: str, value: str) -> str | None:
             capture_output=True, text=True, errors="replace", timeout=10,
             stdin=subprocess.DEVNULL, cwd="/mnt/c" if Path("/mnt/c").is_dir() else None,
         )
-    except (OSError, subprocess.SubprocessError):
+    except (OSError, subprocess.SubprocessError) as exc:
+        _windows_unasked("reg.exe", exc)
+        _note_windows_unasked()
         return None
     match = re.search(
         rf"^\s*{re.escape(value)}\s+REG_(?:EXPAND_)?SZ\s+(.+?)\s*$", result.stdout, re.M
@@ -2734,6 +2771,8 @@ def _detect_by_path(os_type: str, found: list[tuple[str, Path]]) -> None:
 def detect_platforms(os_type: str) -> list[tuple[str, Path]]:
     """Detect installed emulator platforms and their BIOS directories."""
     found: list[tuple[str, Path]] = []
+    if os_type == "wsl":
+        _note_windows_unasked()
 
     if os_type == "android":
         found.extend(_detect_android())

install.sh

@@ -23,7 +23,7 @@ DEFAULT_INSTALL_URL="https://raw.githubusercontent.com/Abdess/retrobios/main/ins
 # curl or wget stop on a cut transfer before the hash is read: the site's
 # build rewrites this line there (scripts/sitebootstrap.py).
 MISMATCH_ADVICE="The download was most likely cut short: try again. Within minutes of an update of this project the two files can come from caches of different ages. Waiting five minutes settles that."
-DEFAULT_INSTALL_SHA256="1096705acbaa531b7e05458cc58b393426b7e1577d0db62bd2cd29e1c8257ca3"
+DEFAULT_INSTALL_SHA256="450cee7625f098d5796452b02ab9c8bffdeaaef89180d2254bbe07ce354bc359"
 MAX_INSTALLER_BYTES=2097152
 
 cleanup() {

install/launchers/index.json

@@ -27,8 +27,8 @@
         {
           "dest": "roms/ports/retrobios/install.py",
           "repo_path": "install.py",
-          "size": 1113525,
-          "sha256": "1096705acbaa531b7e05458cc58b393426b7e1577d0db62bd2cd29e1c8257ca3",
+          "size": 1115328,
+          "sha256": "450cee7625f098d5796452b02ab9c8bffdeaaef89180d2254bbe07ce354bc359",
           "executable": false
         },
         {
@@ -71,8 +71,8 @@
     "muos": {
       "archive": {
         "dest": "ARCHIVE/RetroBIOS.muxapp",
-        "size": 1167152,
-        "sha256": "eaed4292f1bcfdbe613e377b5e6b69933819b71c50b1b2d2f162603743d6b17a"
+        "size": 1168955,
+        "sha256": "1f52731fda2beb3ff9e7aaf7f3d9333853e66b99240b24e4f6b0026368755cb4"
       },
       "members": [
         {
@@ -92,8 +92,8 @@
         {
           "name": "RetroBIOS/install.py",
           "repo_path": "install.py",
-          "size": 1113525,
-          "sha256": "1096705acbaa531b7e05458cc58b393426b7e1577d0db62bd2cd29e1c8257ca3",
+          "size": 1115328,
+          "sha256": "450cee7625f098d5796452b02ab9c8bffdeaaef89180d2254bbe07ce354bc359",
           "executable": false
         },
         {
@@ -166,8 +166,8 @@
         {
           "dest": ".config/modules/retrobios/install.py",
           "repo_path": "install.py",
-          "size": 1113525,
-          "sha256": "1096705acbaa531b7e05458cc58b393426b7e1577d0db62bd2cd29e1c8257ca3",
+          "size": 1115328,
+          "sha256": "450cee7625f098d5796452b02ab9c8bffdeaaef89180d2254bbe07ce354bc359",
           "executable": false
         },
         {

tests/test_install.py

@@ -4511,6 +4511,37 @@ class WindowsSeenFromWsl(unittest.TestCase):
             self.assertEqual(os.environ["ProgramFiles"], "")
 
 
+    def test_windows_not_answering_is_said_not_taken_for_nothing(self):
+        """cmd.exe timing out on the first variable ended the import without
+        a word, and detection said no setup was installed."""
+        calls: list = []
+
+        def slow(argv, **kwargs):
+            calls.append(argv)
+            raise subprocess.TimeoutExpired(argv, kwargs.get("timeout", 10))
+
+        cleared = {name: "" for name in install._WINDOWS_VARIABLES}
+        home = Path(_tempdir(self))
+        err = io.StringIO()
+        with unittest.mock.patch.dict(os.environ, {**cleared, "HOME": str(home)}), \
+                unittest.mock.patch.object(install.subprocess, "run", slow), \
+                unittest.mock.patch.object(Path, "home", return_value=home), \
+                unittest.mock.patch.object(install, "_DETECTION_REFUSED", []), \
+                unittest.mock.patch.object(install.EVENTS, "emit") as emit, \
+                contextlib.redirect_stderr(err):
+            install._enter_wsl()
+            self.assertEqual(len(calls), 1)
+            install.detect_platforms("wsl")
+            install.detect_platforms("wsl")
+        said = err.getvalue()
+        self.assertEqual(said.count("on the Windows side"), 1, said)
+        self.assertIn("cmd.exe did not answer in 10 s", said)
+        kinds = [c.args[0] for c in emit.call_args_list]
+        self.assertEqual(kinds.count("unsearched"), 1)
+        self.assertEqual(emit.call_args_list[kinds.index("unsearched")].kwargs["folder"],
+                         str(self.root))
+
+
 class SteamRetroArchOnMacIsPortable(unittest.TestCase):
     """platform_darwin.m makes the Steam build portable (HAVE_STEAM) with no
     portable.txt: a default system_directory is Application Support's, and

wiki/installer.md

@@ -1160,7 +1160,9 @@ Under WSL both sides are searched. The Windows one is reached through its
 `/mnt/<drive>` mount: a `C:\` path from a rule or a config becomes
 `/mnt/c/...`, and the Windows variables the rules use (`USERPROFILE`,
 `APPDATA`, `LOCALAPPDATA`, `ProgramFiles`) are read through `cmd.exe` when
-WSL does not pass them. A forced `--platform retrobat` falls back to
+WSL does not pass them. When `cmd.exe` or `reg.exe` gives no answer within
+10 seconds or cannot run (interop turned off), the run says the Windows side
+was not searched, never that nothing is installed there. A forced `--platform retrobat` falls back to
 `/mnt/c/RetroBat/bios`. With nothing found, the folder question offers both
 usual folders of a setup that has one on each side: RetroArch's in this Linux
 (`~/.config/retroarch/system`, under Enter) and the Windows one
@@ -1797,7 +1799,7 @@ other schemas under `api/v1/schemas/`.
 | Kind | Keys | When |
 |------|------|------|
 | `start` | `schema`, `installer`, `mode` | First line. `schema` is 1, `installer` the identity `--version` prints, `mode` one of `install`, `check`, `dry-run`, `list` |
-| `unsearched` | `folder`, `reason`, `message` | Before `detect`, once for each folder the search for setups could not look in, this user being refused it or a read failing there (a failing card, a link that loops). What it would hold counts as absent, and the other places are still searched: `detect` then lists what they hold, and an empty `platforms` after an `unsearched` line means nothing was found where the installer could look. `reason` says why in words (`Permission denied`), `message` says it in a sentence |
+| `unsearched` | `folder`, `reason`, `message` | Before `detect`, once for each folder the search for setups could not look in, this user being refused it or a read failing there (a failing card, a link that loops), or under WSL the Windows side when Windows did not answer (`folder` is then the drive mount, `/mnt`). What it would hold counts as absent, and the other places are still searched: `detect` then lists what they hold, and an empty `platforms` after an `unsearched` line means nothing was found where the installer could look. `reason` says why in words (`Permission denied`), `message` says it in a sentence |
 | `detect` | `os`, `os_name`, `platforms` | Once the platforms are known. `os_name` comes from `/etc/os-release`. `platforms` lists `{platform, name, bios_dir}`, and is empty when nothing supported was found |
 | `error` | `stage`, `reason`, `platform`, `message` | The file list could not be read (`stage` is `manifest`): `reason` is `network`, `not_found` or `invalid`, `clock` when the server's certificate was refused and the system clock reads a date before the installer was written, `no_ca` when the machine holds no list of trusted certificates (`SSL_CERT_FILE` names one), `no_ssl` when this Python was built without its `ssl` module and cannot use HTTPS, or `offline` when `--offline` forbids the request. A folder named with `--from` cannot be read (`stage` is `from`, `reason` `not_found`, `not_a_folder` for a file that is no ZIP, `unreadable`, or `system` for the root of the system, `/proc`, `/sys` or `/dev`). The BIOS folder sits under a folder this user cannot open (`stage` is `dest`, `reason` `unreadable`), or is a file or lies under one (`reason` `not_a_folder`), and the run ends with code 1 before anything is written. A platform, target, system, core or emulator named on the command line is unknown or cannot be used here (`stage` is `option`, `reason` `unknown`, `platform` the platform it was checked against or the name typed), refused before any download with code 2. The BIOS folder cannot be created (`stage` is `dest`, `reason` `not_writable`): a `summary` follows with what the run installed before it. Two systems are detected on one machine and no `--dest` names the folder (`stage` is `detect`, `reason` `conflict`). The platform named with `--platform` is found nowhere and no folder can be assumed for it: a card system with no card named, a portable emulator, Batocera or Recalbox named on a computer (their folder is the `bios` folder of their SHARE drive), or no usual folder on this system or one set aside behind a folder this user cannot open (`stage` is `detect`, `reason` `not_found`). So is a platform named by a file list or a pack, in a run without questions where it is found nowhere here. A `--dest` refused as the card of the system named carries the same `stage` and `reason`: another system's card, a folder inside a card, a drive with none of the files its card always has, or a folder that does not exist. `message` says it in words, and is the only thing that tells these cases apart |
 | `scanned` | `folder`, `files`, `truncated`, `other_drives` | Each folder named with `--from`, once read and before `detect`. `files` counts the files found, `truncated` is true when the search stopped at 200,000 of them, and `other_drives` lists the folders below it on another drive, which were not entered |