docs: quote the bootstrap's real fingerprint error

install.ps1

@@ -46,7 +46,7 @@ try {
         }
         $actual = (Get-FileHash -LiteralPath $temporary -Algorithm SHA256).Hash.ToLowerInvariant()
         if ($actual -ne $expected.ToLowerInvariant()) {
-            throw "The downloaded installer does not match its expected fingerprint. Nothing was run and nothing was written. The download was most likely cut short; try again, on another network if possible."
+            throw "The downloaded installer does not match its expected fingerprint. Nothing was run and nothing was written. 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."
         }
         $installer = $temporary
     }

install.sh

@@ -91,7 +91,9 @@ if [ -z "$INSTALLER" ] || [ ! -f "$INSTALLER" ]; then
   if [ "$actual" != "$expected" ]; then
     echo "Error: the downloaded installer does not match its expected fingerprint." >&2
     echo "  Nothing was run and nothing was written." >&2
-    echo "  The download was most likely cut short. Try again, on another network if possible." >&2
+    echo "  The download was most likely cut short: try again. Within minutes of an update" >&2
+    echo "  of this project the two files can come from caches of different ages; waiting" >&2
+    echo "  five minutes settles that." >&2
     exit 1
   fi
   INSTALLER="$TEMP_INSTALLER"

tests/test_install.py

@@ -2657,5 +2657,20 @@ class TheProgressLineFitsTheTerminal(unittest.TestCase):
                 self.assertIn("%", line)
 
 
+
+class ThePagesQuoteTheBootstrapsOwnWords(unittest.TestCase):
+    """The installer page and the FAQ quoted "install.py SHA-256 mismatch",
+    a message the bootstraps no longer print."""
+
+    def test_the_quoted_message_is_printed(self):
+        quoted = "does not match its expected"
+        for wrapper in ("install.sh", "install.ps1"):
+            self.assertIn(quoted, (REPO_ROOT / wrapper).read_text(encoding="utf-8"))
+        for page in ("wiki/installer.md", "wiki/faq.md"):
+            text = (REPO_ROOT / page).read_text(encoding="utf-8")
+            self.assertNotIn("SHA-256 mismatch`", text)
+            self.assertIn(quoted, " ".join(text.split()))
+
+
 if __name__ == "__main__":
     unittest.main()

wiki/faq.md

@@ -103,8 +103,8 @@ The `--verbose` flag shows source references and expected values from the emulat
 The one-liner runs a small bootstrap, not the installer. That bootstrap fetches
 `install.py` over HTTPS only, refuses anything over 2 MB, and requires its
 SHA-256 to equal the value written inside the bootstrap itself. A substituted
-installer aborts with `install.py SHA-256 mismatch` before a single line of it
-runs.
+installer aborts with "the downloaded installer does not match its expected
+fingerprint" before a single line of it runs.
 
 The installer then verifies every file it downloads against the size, SHA-256
 and SHA-1 the manifest declares, and moves it into place only once those match.

wiki/installer.md

@@ -52,8 +52,11 @@ pinned raw URL. A URL with any other scheme is refused outright.
 
 They cap the download at 2 MB and require the SHA-256 to equal the 64 hex
 characters embedded in the wrapper, `RETROBIOS_INSTALL_SHA256` when set. A
-mismatch aborts with `install.py SHA-256 mismatch` and nothing runs. Any change
-to `install.py` therefore means recomputing that pin in both wrappers.
+mismatch aborts with "the downloaded installer does not match its expected
+fingerprint" and nothing runs. Right after an update of this project the
+wrapper and `install.py` can come from caches a few minutes apart, which reads
+the same way: waiting five minutes settles it. Any change to `install.py`
+therefore means recomputing that pin in both wrappers.
 
 They locate a Python 3.8 or newer interpreter (`python3` then `python` on
 POSIX, `py -3` then `python3` then `python` on Windows) and refuse to continue