fix: skip data trees a read-only folder refuses

A BIOS folder this user cannot write no longer tries each data tree's archive and blames its URL with a raw errno. The tree is counted failed for the same cause as the BIOS files, so the summary keeps its one line and its advice.

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 = "78ef177611168c1c7699cafa8982f901aaaf5342b6c55d6e158ba18fb4cc0ae2"
+    $defaultInstallSha256 = "c8cf4b65474279c30c2e1781028d3e05f195e26dd759a98a37db3477b6dd3014"
     $maximumInstallerBytes = 2MB
     $installerExit = 0
     $installer = if ($PSScriptRoot) { Join-Path $PSScriptRoot "install.py" } else { $null }

install.py

@@ -7198,7 +7198,12 @@ def install_data_directory(entry: dict, bios_path: Path,
         # Kept apart, so the advice is the offline one, not the network's.
         counts["error"] = OfflineReason(str(exc))
     except (urllib.error.URLError, OSError, ValueError, tarfile.TarError) as exc:
-        counts["error"] = str(getattr(exc, "reason", None) or exc)
+        # The tree's folder refused, not the source: said as the BIOS files
+        # say it, never as an archive that could not be read.
+        counts["error"] = (NOT_WRITABLE if isinstance(exc, OSError)
+                           and not isinstance(exc, urllib.error.URLError)
+                           and _write_refused(exc) and not _folder_writable(root)
+                           else str(getattr(exc, "reason", None) or exc))
     except _MEMBER_ERRORS as exc:
         # A damaged, encrypted or unsupported member, in words.
         counts["error"] = unreadable_words(exc)
@@ -15838,8 +15843,19 @@ def _install(args: argparse.Namespace, real_stdout: TextIO) -> None:
         # PPSSPP's assets. Fetched from their source archive, each file
         # checked against the hash the list records.
         if data_dirs and not total_interrupted:
-            print("\nData directories:")
+            # A tree whose folder this user cannot write is not fetched: the
+            # BIOS files above already said the cause and its remedy, and
+            # each archive was named as unreadable.
+            writable = []
             for entry, state in data_states:
+                if state[1] and not _folder_writable(state[0]):
+                    failures.append((entry["ref"], NOT_WRITABLE))
+                    total_errors += 1
+                else:
+                    writable.append((entry, state))
+            if writable:
+                print("\nData directories:")
+            for entry, state in writable:
                 counts = install_data_directory(entry, bios_path, state)
                 total_downloaded += counts["installed"]
                 data_landed += counts["installed"]
@@ -15866,7 +15882,10 @@ def _install(args: argparse.Namespace, real_stdout: TextIO) -> None:
                                  f", {counts['changed'] + counts['absent']} no longer in "
                                  "the source (the pack has them)")
                     print(line)
-                if counts["error"]:
+                if counts["error"] == NOT_WRITABLE:
+                    failures.append((entry["ref"], NOT_WRITABLE))
+                    total_errors += 1
+                elif counts["error"]:
                     print(f"  {entry['ref']}: could not read "
                           f"{LOCAL.pack.name if LOCAL.pack is not None else entry['url']}: "
                           f"{counts['error']}", file=sys.stderr)

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="78ef177611168c1c7699cafa8982f901aaaf5342b6c55d6e158ba18fb4cc0ae2"
+DEFAULT_INSTALL_SHA256="c8cf4b65474279c30c2e1781028d3e05f195e26dd759a98a37db3477b6dd3014"
 MAX_INSTALLER_BYTES=2097152
 
 cleanup() {

install/launchers/index.json

@@ -27,8 +27,8 @@
         {
           "dest": "roms/ports/retrobios/install.py",
           "repo_path": "install.py",
-          "size": 1100388,
-          "sha256": "78ef177611168c1c7699cafa8982f901aaaf5342b6c55d6e158ba18fb4cc0ae2",
+          "size": 1101457,
+          "sha256": "c8cf4b65474279c30c2e1781028d3e05f195e26dd759a98a37db3477b6dd3014",
           "executable": false
         },
         {
@@ -71,8 +71,8 @@
     "muos": {
       "archive": {
         "dest": "ARCHIVE/RetroBIOS.muxapp",
-        "size": 1154015,
-        "sha256": "03bcbdf8385808576afb0899860e5f11af37a9aee709b72481064e7a0ee79afa"
+        "size": 1155084,
+        "sha256": "41b72bf029de9d855312e472cc9a10046f71692a55e02c4a959efdf4201505ad"
       },
       "members": [
         {
@@ -92,8 +92,8 @@
         {
           "name": "RetroBIOS/install.py",
           "repo_path": "install.py",
-          "size": 1100388,
-          "sha256": "78ef177611168c1c7699cafa8982f901aaaf5342b6c55d6e158ba18fb4cc0ae2",
+          "size": 1101457,
+          "sha256": "c8cf4b65474279c30c2e1781028d3e05f195e26dd759a98a37db3477b6dd3014",
           "executable": false
         },
         {
@@ -166,8 +166,8 @@
         {
           "dest": ".config/modules/retrobios/install.py",
           "repo_path": "install.py",
-          "size": 1100388,
-          "sha256": "78ef177611168c1c7699cafa8982f901aaaf5342b6c55d6e158ba18fb4cc0ae2",
+          "size": 1101457,
+          "sha256": "c8cf4b65474279c30c2e1781028d3e05f195e26dd759a98a37db3477b6dd3014",
           "executable": false
         },
         {

tests/test_install_offline.py

@@ -951,6 +951,33 @@ class OfflineLeavesFilesMissing(Scratch):
         self.assertNotIn("could not read", proc.stderr)
         self.assertNotIn("no longer in the source", proc.stdout)
 
+    @unittest.skipIf(os.name == "nt" or os.geteuid() == 0,
+                     "a read-only folder is refused by POSIX permissions")
+    def test_a_tree_in_a_folder_not_writable_is_not_fetched(self):
+        """A read-only card blamed each data archive's URL with a raw
+        errno, and that second cause split the one-line summary."""
+        listed = manifest()
+        listed["data_directories"] = [{
+            "ref": "bluemsx", "dest": "Machines", "type": "zip",
+            "url": "https://example.invalid/blueMSX.zip", "systems": ["nintendo-gba"],
+            "files": {"a.txt": {"sha1": _sha1(b"a"), "size": 1}},
+        }, {
+            "ref": "fbneo-cheats", "dest": "fbneo/cheats", "type": "zip",
+            "url": "https://example.invalid/cheats.zip", "systems": ["nintendo-gba"],
+            "files": {"b.txt": {"sha1": _sha1(b"b"), "size": 1}},
+        }]
+        self.list.write_text(json.dumps(listed))
+        self.complete()
+        self.dest.chmod(0o555)
+        self.addCleanup(self.dest.chmod, 0o755)
+        proc = self.run_installer("--manifest", str(self.list), "--no-input")
+        out = proc.stdout + proc.stderr
+        self.assertEqual(proc.returncode, 2, out)
+        self.assertNotIn("could not read", out)
+        self.assertNotIn("Errno", out)
+        self.assertNotIn("Data directories:", out)
+        self.assertIn("failed: 2 files (folder not writable), first bluemsx", out)
+
 
 class OneOfflineVocabulary(Scratch):
     """--offline said one