diff --git a/local/build-all.R b/local/build-all.R
index 349092f..eda92e9 100644
--- a/local/build-all.R
+++ b/local/build-all.R
@@ -201,15 +201,10 @@ s3_cache_paths <- readRDS("/mnt/cache/packages/s3_cache.rds")
 # nothing; hand it nothing and it rebuilds what it already has. amd64/resolute
 # recompiled 8683 packages that way.
 select_cache_for_pass <- function(paths, sensitive_only, r_minor) {
-  # A cache written before #191 holds bare basenames. Filtering those by path
-  # would select nothing and trigger a full rebuild, so use them as they are;
-  # #190's staleness check replaces it on the next pipeline anyway.
-  #
-  # The format is read from the marker `packages-to-build.R` sets, not guessed
-  # from the content: a slot-relative cache with no per-minor or Archive object
-  # holds bare names too, and treating that as legacy would hand a per-minor
-  # pass the flat slot's binaries and build nothing.
-  if (!isTRUE(attr(paths, "slot_relative"))) {
+  # A cache written before this change holds bare basenames. Filtering those by
+  # path would select nothing and trigger a full rebuild, so use them as they
+  # are; #190's staleness check replaces it on the next pipeline anyway.
+  if (!any(grepl("/", paths, fixed = TRUE))) {
     message("S3 cache is in the legacy basename format; using it unfiltered.")
     return(paths)
   }
diff --git a/local/packages-to-build.R b/local/packages-to-build.R
index 9e17f4d..64a2f5f 100644
--- a/local/packages-to-build.R
+++ b/local/packages-to-build.R
@@ -190,44 +190,14 @@ binary_cache <- setdiff(file_names, source_served)
 # So the cache keeps the path relative to the slot, and `build-all.R` selects
 # the part that matches the pass it is running: the flat slot for the primary,
 # `<minor>/` for a per-minor pass.
-#
-# `s3_dir_ls()` returns keys with the `s3://` scheme attached, so stripping the
-# prefix as a fixed substring takes it out of the middle and leaves
-# `s3://4.4/curl_1.0.tar.gz`. That leading scheme defeats the `^<minor>/` test
-# downstream, so every per-minor object is read as a flat-slot object: the
-# sensitive passes see an empty cache and recompile everything they already
-# have. Anchor the pattern and swallow the scheme with it.
 contrib_prefix <- sprintf(
-  "^(s3://)?devxy-rpkgs-binaries/%s/%s/latest/src/contrib/",
+  "devxy-rpkgs-binaries/%s/%s/latest/src/contrib/",
   arch,
   codename
 )
-relative_paths <- sub(contrib_prefix, "", s3_pkgs)
-
-# The strip is load-bearing and fails silently, so assert it. Both counts are
-# derived from the same listing and use the same shape of pattern, so they must
-# agree exactly; a mismatch means the prefix no longer describes the keys.
-stripped_per_minor <- grepl("^[0-9]+\\.[0-9]+/[^/]+$", relative_paths)
-if (sum(stripped_per_minor) != sum(per_minor_object)) {
-  stop(sprintf(
-    paste0(
-      "S3 prefix strip failed: %d per-minor objects in the listing, %d after ",
-      "stripping /%s/. Example key: %s"
-    ),
-    sum(per_minor_object),
-    sum(stripped_per_minor),
-    contrib_prefix,
-    if (any(per_minor_object)) {
-      s3_pkgs[which(per_minor_object)[1L]]
-    } else {
-      "<none>"
-    }
-  ))
-}
+relative_paths <- sub(contrib_prefix, "", s3_pkgs, fixed = TRUE)
 source_basenames <- source_served
-existence_cache <- relative_paths[
-  !basename(relative_paths) %in% source_basenames
-]
+existence_cache <- relative_paths[!basename(relative_paths) %in% source_basenames]
 cat(sprintf(
   "S3 cache: %d objects, %d served as CRAN source, %d usable binaries\n",
   length(file_names),
@@ -238,12 +208,6 @@ cat(sprintf(
 # Save the S3 file listing for the build step to use as s3_package_cache.
 # This avoids loading s3fs/reticulate in the build container, saving memory for
 # the dependency-installer subprocesses
-# Mark the format explicitly. `build-all.R` has to tell a slot-relative cache
-# from a pre-#191 basename one, and sniffing for a "/" cannot: a new-format
-# cache for a slot with no per-minor or Archive objects holds bare names too,
-# and would be read as legacy and used unfiltered, which makes a per-minor pass
-# believe the flat slot's binaries are its own and build nothing.
-attr(existence_cache, "slot_relative") <- TRUE
 saveRDS(existence_cache, "/mnt/cache/packages/s3_cache.rds")
 # Built from the filtered listing, not the raw one: `s3_dt` is subtracted from
 # the build list below, so a source fallback left in here would exclude the very
diff --git a/scripts/purge_cdn_zone.sh b/scripts/purge_cdn_zone.sh
index 8e85cb6..6c07eef 100755
--- a/scripts/purge_cdn_zone.sh
+++ b/scripts/purge_cdn_zone.sh
@@ -70,8 +70,8 @@ resolve_zone_id() {
   zone_id=$(
     jq -r --arg hostname "${zone}" \
       '(if type == "object" then (.Items // []) else . end)[]
-        | select(any(.Hostnames[]?; .Value == $hostname))
-        | .Id' \
+         | select(any(.Hostnames[]?; .Value == $hostname))
+         | .Id' \
       "${response_file}"
   )
   rm -f "${response_file}"