Closes #177

.github/workflows/ci.yml

@@ -63,13 +63,14 @@ jobs:
       - run: cargo test --workspace
 
   release-invariants:
-    # #176: turn the #161-class privacy invariant into a permanent gate. CI's
+    # #176/#177: turn the #161-class privacy invariant into a permanent gate. CI's
     # other jobs only compile/test the DEBUG profile, so a dropped
-    # `#[cfg(debug_assertions)]` guard (e.g. a bad merge on the #64 bleed dump or a
-    # #108 dev flag) is invisible to them and only surfaces at tag time. This job
-    # compiles livecap-app in RELEASE and asserts the debug-only env-escape NAMES
-    # are absent from the binary — they exist only inside `#[cfg(debug_assertions)]`
-    # items, so a release build compiles them out entirely (#146/#161).
+    # `#[cfg(debug_assertions)]` guard (e.g. a bad merge on the #64 bleed dump, a
+    # #108 dev flag, or the #177 model-base-url knob) is invisible to them and only
+    # surfaces at tag time. This job compiles livecap-app in RELEASE and asserts the
+    # debug-only env-escape NAMES are absent from the binary — they exist only
+    # inside `#[cfg(debug_assertions)]` items, so a release build compiles them out
+    # entirely (#146/#161/#177).
     runs-on: macos-14
     steps:
       - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
@@ -98,7 +99,7 @@ jobs:
           # These env vars are read ONLY inside #[cfg(debug_assertions)] items, so a
           # release build must contain none of their names. A hit means a guard was
           # dropped and the shipped binary regained a covert env path (#161-class).
-          FORBIDDEN="LIVECAP_BLEED_DUMP_DIR LIVECAP_CAPTURE_VISIBLE LIVECAP_AUTOSTART LIVECAP_UI_PROBE"
+          FORBIDDEN="LIVECAP_BLEED_DUMP_DIR LIVECAP_CAPTURE_VISIBLE LIVECAP_AUTOSTART LIVECAP_UI_PROBE LIVECAP_MODEL_BASE_URL"
           fail=0
           for name in $FORBIDDEN; do
             if strings "$BIN" | grep -q "$name"; then

crates/livecap-core/src/model.rs

@@ -33,13 +33,29 @@ const HF_REPO: &str = "https://huggingface.co/ggerganov/whisper.cpp";
 /// source — [`pointer_url`] is pinned to the official [`HF_REPO`] — so an
 /// overridden host cannot serve a fake LFS pointer alongside a matching fake
 /// blob; any blob that does not match the OFFICIAL digest fails verification.
+// Release builds never read this env var (#177), so the const is unused there —
+// which is the point: an unused const emits no string, so the release binary
+// carries no `LIVECAP_MODEL_BASE_URL` symbol (asserted by the release-invariants
+// CI gate). The `allow(dead_code)` only silences the release-profile warning.
+#[cfg_attr(not(debug_assertions), allow(dead_code))]
 const MODEL_BASE_URL_ENV: &str = "LIVECAP_MODEL_BASE_URL";
 
-/// The effective BLOB download base URL (env override or the official repo).
+/// The effective BLOB download base URL. Debug builds honor the
+/// [`MODEL_BASE_URL_ENV`] dev-run knob (#110 download-failure fallback); RELEASE
+/// builds ALWAYS use the official [`HF_REPO`] — the env read is compiled out
+/// entirely (#177, mirroring #146/#161), so a shipped binary exposes no such knob
+/// and its model-download host can't be redirected. The pure
+/// [`base_url_or_default`] core stays testable in both profiles.
+#[cfg(debug_assertions)]
 fn blob_base_url() -> String {
     base_url_or_default(std::env::var(MODEL_BASE_URL_ENV).ok())
 }
 
+#[cfg(not(debug_assertions))]
+fn blob_base_url() -> String {
+    base_url_or_default(None)
+}
+
 /// Pure core of [`blob_base_url`]: `None`/blank → the official repo. Trailing
 /// slashes are trimmed so the joined download URLs stay well-formed.
 fn base_url_or_default(overridden: Option<String>) -> String {