fix(sandbox): fail-fast on stalled HTTP clones to escape NAT blackholes

packages/sandbox/daemon/setup/clone.ts

@@ -47,6 +47,13 @@ const TRANSIENT_ERRORS = [
   "unexpected disconnect",
   "Connection reset by peer",
   "Connection timed out",
+  // libcurl CURLE_OPERATION_TIMEDOUT triggered by http.lowSpeedLimit/Time —
+  // fires when the egress NAT silently drops in-flight packets (e.g. fck-nat
+  // ASG instance refresh) and the stream stalls below the threshold.
+  "Operation too slow",
+  "transfer closed with",
+  "RPC failed",
+  "the remote end hung up",
 ];
 const CLONE_MAX_RETRIES = 3;
 const CLONE_RETRY_DELAY_MS = 3000;

packages/sandbox/image/Dockerfile

@@ -44,6 +44,13 @@ RUN pip3 install --break-system-packages --no-cache-dir \
 ENV LANG=en_US.UTF-8 \
     LC_ALL=en_US.UTF-8
 
+# Convert silent stalls (NAT instance replacement, PMTUD blackholes, mid-stream
+# packet drops) into fast errors that the daemon's clone retry loop can catch.
+# Without this, libcurl waits on TCP keepalive (~2h default) and the clone
+# hangs at "Receiving objects" indefinitely.
+RUN git config --system http.lowSpeedLimit 1000 \
+  && git config --system http.lowSpeedTime 30
+
 # Non-root sandbox user. The bun image comes with a 'bun' user (UID 1000),
 # but we drop privileges further by replacing it with a 'sandbox' user.
 RUN userdel --remove bun \

packages/sandbox/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@decocms/sandbox",
-  "version": "0.4.5",
+  "version": "0.4.6",
   "type": "module",
   "description": "Sandbox runner for isolated per-user containerised tool execution",
   "scripts": {