fix: name release assets as GitHub serves them

scripts/generate_pack.py

@@ -76,7 +76,7 @@ import slot as slot_mod
 import slots
 import split_pack
 from deterministic_zip import _FIXED_DATE_TIME, rebuild_zip_deterministic
-from largefiles import asset_name, load_registered_paths
+from largefiles import asset_name, load_registered_paths, published_asset_name
 from nativemode import (
     digest_algorithm,
     hash_mismatch_excludes_file,
@@ -3226,8 +3226,14 @@ def _repo_relative(local_path: str, repo_root: str) -> str:
 
 
 def _release_asset_name(local_path: str, repo_root: str) -> str:
-    """The large-files asset install.py downloads for a gitignored file."""
-    return asset_name(_repo_relative(local_path, repo_root), sorted(_registered(repo_root)))
+    """The large-files asset install.py downloads for a gitignored file.
+
+    The name GitHub serves, not the one uploaded: a space in the path came
+    back as a 404 for an installer asking for it verbatim.
+    """
+    return published_asset_name(
+        asset_name(_repo_relative(local_path, repo_root), sorted(_registered(repo_root)))
+    )
 
 
 def _get_repo_path(sha1: str, db: dict) -> str:

scripts/generate_site.py

@@ -2018,11 +2018,12 @@ def _fetch_url(path: str) -> str:
             LARGE_FILES_RELEASE,
             asset_names,
             load_registered_paths,
+            published_asset_name,
         )
 
         _RELEASE_ASSET_NAMES = {
             registered: f"{REPO_URL}/releases/download/{LARGE_FILES_RELEASE}/"
-            + urllib.parse.quote(name.replace(" ", "."))
+            + urllib.parse.quote(published_asset_name(name))
             for registered, name in asset_names(load_registered_paths()).items()
         }
     return _RELEASE_ASSET_NAMES.get(path) or (

scripts/largefiles.py

@@ -88,6 +88,11 @@ def asset_name(path: str, registered: Iterable[str]) -> str:
     return asset_names([*registered, path])[path]
 
 
+def published_asset_name(name: str) -> str:
+    """The name GitHub serves an asset under: it publishes a space as a dot."""
+    return name.replace(" ", ".")
+
+
 def asset_candidates(name: str, registered: Iterable[str]) -> list[str]:
     """Assets that may hold *name*, a registered path or a bare file name.