fix: pass -v and every short flag to install.py

A [Parameter()] attribute made install.ps1 an advanced script: its common
parameters took -v (-Verbose), -vb, -d and -ea before install.py saw them,
and the scriptblock form printed PowerShell's own VERBOSE lines. The
wrapper now forwards $args as typed.

install.ps1

@@ -3,12 +3,11 @@
 # Everything runs in a script block of its own: piped into iex, the script
 # would otherwise leave its variables and $ErrorActionPreference = "Stop"
 # in the user's session, where every later error would stop their commands.
+# Neither the script nor the block declares a parameter: one [Parameter()]
+# attribute makes it an advanced one, whose common parameters took -v
+# (-Verbose), -vb, -d (-Debug) and -ea before install.py could see them.
 & {
-    [CmdletBinding()]
-    param(
-        [Parameter(ValueFromRemainingArguments = $true)]
-        [string[]]$InstallerArguments
-    )
+    $InstallerArguments = @($args)
 
     $ErrorActionPreference = "Stop"
     $defaultInstallUrl = "https://raw.githubusercontent.com/Abdess/retrobios/main/install.py"

tests/test_install.py

@@ -2276,6 +2276,29 @@ class ThePowerShellWrapperPassesTheStatusOn(unittest.TestCase):
                 self.assertNotIn("installer failed", proc.stdout + proc.stderr)
 
 
+class ThePowerShellWrapperPassesEveryArgument(unittest.TestCase):
+    """A [Parameter()] attribute made install.ps1 an advanced script, whose
+    common parameters took -v (as -Verbose), -vb, -d and -ea: the documented
+    `-v` never reached install.py."""
+
+    @unittest.skipUnless(shutil.which("pwsh"), "needs PowerShell")
+    def test_short_flags_reach_the_installer(self):
+        folder = Path(_tempdir(self))
+        shutil.copy(REPO_ROOT / "install.ps1", folder / "install.ps1")
+        (folder / "install.py").write_text(
+            "import json, sys\nprint(json.dumps(sys.argv[1:]))\n"
+        )
+        for args in (["-v", "--check"], ["-vb"], ["-Verbose"], ["-d", "-ea", "x"],
+                     ["--platform", "a b"], []):
+            with self.subTest(args=args):
+                proc = subprocess.run(
+                    ["pwsh", "-NoProfile", "-File", str(folder / "install.ps1"), *args],
+                    capture_output=True, text=True, timeout=120,
+                )
+                self.assertEqual(proc.returncode, 0, proc.stderr)
+                self.assertEqual(json.loads(proc.stdout), args)
+
+
 @unittest.skipIf(os.name == "nt" or os.geteuid() == 0, "needs a folder this user cannot write")
 class AnUnwritableFolderIsCodeTwo(unittest.TestCase):
     """A BIOS folder that could not be created ended with 1, while the same

wiki/installer.md

@@ -510,7 +510,9 @@ fields, the installer refuses to narrow rather than install everything.
 
 `install.ps1` passes the installer's code on unchanged: run as a file it exits
 with it, run through `irm \| iex` it sets `$LASTEXITCODE` (an `exit` there
-would close the PowerShell window). Its body runs in a script block of its own,
+would close the PowerShell window). It declares no parameter of its own, so
+every argument reaches `install.py` as typed, short forms such as `-v`
+included. Its body runs in a script block of its own,
 so `irm \| iex` leaves neither its variables nor its `$ErrorActionPreference`
 in the session.