diff --git a/src/Craned/TaskManager.cpp b/src/Craned/TaskManager.cpp
index d4b60471..b705b784 100644
--- a/src/Craned/TaskManager.cpp
+++ b/src/Craned/TaskManager.cpp
@@ -641,16 +641,18 @@ CraneErr TaskManager::SpawnProcessInInstance_(
     // Move the ownership of ProcessInstance into the TaskInstance.
     instance->processes.emplace(child_pid, std::move(process));
 
-    close(io_in_sock_pair[1]);
-    close(io_out_sock_pair[1]);
-    close(ctrl_sock_pair[1]);
     int ctrl_fd = ctrl_sock_pair[0];
-    bool ok;
+    close(ctrl_sock_pair[1]);
+    if (instance->IsCrun()) {
+      close(io_in_sock_pair[1]);
+      close(io_out_sock_pair[1]);
+    }
 
     setegid(saved_priv.gid);
     seteuid(saved_priv.uid);
     setgroups(0, nullptr);
 
+    bool ok;
     FileInputStream istream(ctrl_fd);
     FileOutputStream ostream(ctrl_fd);
     CanStartMessage msg;
@@ -691,10 +693,16 @@ CraneErr TaskManager::SpawnProcessInInstance_(
     // subprocess should continue to exec().
     msg.set_ok(true);
     ok = SerializeDelimitedToZeroCopyStream(msg, &ostream);
-    ok &= ostream.Flush();
     if (!ok) {
-      CRANE_ERROR("Failed to send ok=true to subprocess {} for task #{}",
-                  child_pid, instance->task.task_id());
+      CRANE_ERROR("Failed to serialize msg to ostream: {}",
+                  strerror(ostream.GetErrno()));
+    }
+
+    if (ok) ok &= ostream.Flush();
+    if (!ok) {
+      CRANE_ERROR("Failed to send ok=true to subprocess {} for task #{}: {}",
+                  child_pid, instance->task.task_id(),
+                  strerror(ostream.GetErrno()));
       close(ctrl_fd);
 
       // Communication failure caused by process crash or grpc error.
@@ -707,10 +715,15 @@ CraneErr TaskManager::SpawnProcessInInstance_(
       return CraneErr::kOk;
     }
 
-    ParseDelimitedFromZeroCopyStream(&child_process_ready, &istream, nullptr);
-    if (!msg.ok()) {
-      CRANE_ERROR("Failed to read protobuf from subprocess {} of task #{}",
-                  child_pid, instance->task.task_id());
+    ok = ParseDelimitedFromZeroCopyStream(&child_process_ready, &istream,
+                                          nullptr);
+    if (!ok || !msg.ok()) {
+      if (!ok)
+        CRANE_ERROR("Socket child endpoint failed: {}",
+                    strerror(istream.GetErrno()));
+      if (!msg.ok())
+        CRANE_ERROR("False from subprocess {} of task #{}", child_pid,
+                    instance->task.task_id());
       close(ctrl_fd);
 
       // See comments above.
@@ -768,8 +781,18 @@ CraneErr TaskManager::SpawnProcessInInstance_(
     ChildProcessReady child_process_ready;
     bool ok;
 
-    ParseDelimitedFromZeroCopyStream(&msg, &istream, nullptr);
-    if (!msg.ok()) std::abort();
+    ok = ParseDelimitedFromZeroCopyStream(&msg, &istream, nullptr);
+    if (!ok || !msg.ok()) {
+      if (!ok) {
+        int err = istream.GetErrno();
+        CRANE_ERROR("Failed to read socket from parent: {}", strerror(err));
+      }
+
+      if (!msg.ok())
+        CRANE_ERROR("Parent process ask not to start the subprocess.");
+
+      std::abort();
+    }
 
     if (instance->task.type() == crane::grpc::Batch) {
       int stdout_fd, stderr_fd;