diff --git a/lldb/include/lldb/Host/Debug.h b/lldb/include/lldb/Host/Debug.h
--- a/lldb/include/lldb/Host/Debug.h
+++ b/lldb/include/lldb/Host/Debug.h
@@ -130,12 +130,8 @@
 
 struct ThreadStopInfo {
   lldb::StopReason reason;
+  uint32_t signo;
   union {
-    // eStopReasonSignal
-    struct {
-      uint32_t signo;
-    } signal;
-
     // eStopReasonException
     struct {
       uint64_t type;
diff --git a/lldb/source/Plugins/Process/FreeBSD/NativeThreadFreeBSD.cpp b/lldb/source/Plugins/Process/FreeBSD/NativeThreadFreeBSD.cpp
--- a/lldb/source/Plugins/Process/FreeBSD/NativeThreadFreeBSD.cpp
+++ b/lldb/source/Plugins/Process/FreeBSD/NativeThreadFreeBSD.cpp
@@ -81,7 +81,7 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonSignal;
-  m_stop_info.details.signal.signo = signo;
+  m_stop_info.signo = signo;
 
   m_stop_description.clear();
   if (info) {
@@ -100,19 +100,19 @@
 void NativeThreadFreeBSD::SetStoppedByBreakpoint() {
   SetStopped();
   m_stop_info.reason = StopReason::eStopReasonBreakpoint;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadFreeBSD::SetStoppedByTrace() {
   SetStopped();
   m_stop_info.reason = StopReason::eStopReasonTrace;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadFreeBSD::SetStoppedByExec() {
   SetStopped();
   m_stop_info.reason = StopReason::eStopReasonExec;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadFreeBSD::SetStoppedByWatchpoint(uint32_t wp_index) {
@@ -127,7 +127,7 @@
   SetStopped();
   m_stop_description = ostr.str();
   m_stop_info.reason = StopReason::eStopReasonWatchpoint;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadFreeBSD::SetStoppedByFork(lldb::pid_t child_pid,
@@ -135,6 +135,7 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonFork;
+  m_stop_info.signo = SIGTRAP;
   m_stop_info.details.fork.child_pid = child_pid;
   m_stop_info.details.fork.child_tid = child_tid;
 }
@@ -144,6 +145,7 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonVFork;
+  m_stop_info.signo = SIGTRAP;
   m_stop_info.details.fork.child_pid = child_pid;
   m_stop_info.details.fork.child_tid = child_tid;
 }
@@ -152,13 +154,14 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonVForkDone;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadFreeBSD::SetStoppedWithNoReason() {
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonNone;
-  m_stop_info.details.signal.signo = 0;
+  m_stop_info.signo = 0;
 }
 
 void NativeThreadFreeBSD::SetStopped() {
diff --git a/lldb/source/Plugins/Process/Linux/NativeThreadLinux.cpp b/lldb/source/Plugins/Process/Linux/NativeThreadLinux.cpp
--- a/lldb/source/Plugins/Process/Linux/NativeThreadLinux.cpp
+++ b/lldb/source/Plugins/Process/Linux/NativeThreadLinux.cpp
@@ -48,19 +48,19 @@
     return;
   case eStopReasonTrace:
     log.Printf("%s: %s trace, stopping signal 0x%" PRIx32, __FUNCTION__, header,
-               stop_info.details.signal.signo);
+               stop_info.signo);
     return;
   case eStopReasonBreakpoint:
     log.Printf("%s: %s breakpoint, stopping signal 0x%" PRIx32, __FUNCTION__,
-               header, stop_info.details.signal.signo);
+               header, stop_info.signo);
     return;
   case eStopReasonWatchpoint:
     log.Printf("%s: %s watchpoint, stopping signal 0x%" PRIx32, __FUNCTION__,
-               header, stop_info.details.signal.signo);
+               header, stop_info.signo);
     return;
   case eStopReasonSignal:
     log.Printf("%s: %s signal 0x%02" PRIx32, __FUNCTION__, header,
-               stop_info.details.signal.signo);
+               stop_info.signo);
     return;
   case eStopReasonException:
     log.Printf("%s: %s exception type 0x%02" PRIx64, __FUNCTION__, header,
@@ -68,7 +68,7 @@
     return;
   case eStopReasonExec:
     log.Printf("%s: %s exec, stopping signal 0x%" PRIx32, __FUNCTION__, header,
-               stop_info.details.signal.signo);
+               stop_info.signo);
     return;
   case eStopReasonPlanComplete:
     log.Printf("%s: %s plan complete", __FUNCTION__, header);
@@ -285,7 +285,7 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonSignal;
-  m_stop_info.details.signal.signo = signo;
+  m_stop_info.signo = signo;
 
   m_stop_description.clear();
   if (info) {
@@ -371,7 +371,7 @@
   // If we are stopped by a signal, return the signo.
   if (signo && m_state == StateType::eStateStopped &&
       m_stop_info.reason == StopReason::eStopReasonSignal) {
-    *signo = m_stop_info.details.signal.signo;
+    *signo = m_stop_info.signo;
   }
 
   // Regardless, we are stopped.
@@ -398,14 +398,14 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonExec;
-  m_stop_info.details.signal.signo = SIGSTOP;
+  m_stop_info.signo = SIGSTOP;
 }
 
 void NativeThreadLinux::SetStoppedByBreakpoint() {
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonBreakpoint;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
   m_stop_description.clear();
 }
 
@@ -434,7 +434,7 @@
   m_stop_description = ostr.str();
 
   m_stop_info.reason = StopReason::eStopReasonWatchpoint;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
 }
 
 bool NativeThreadLinux::IsStoppedAtBreakpoint() {
@@ -451,7 +451,7 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonTrace;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadLinux::SetStoppedByFork(bool is_vfork, lldb::pid_t child_pid) {
@@ -459,6 +459,7 @@
 
   m_stop_info.reason =
       is_vfork ? StopReason::eStopReasonVFork : StopReason::eStopReasonFork;
+  m_stop_info.signo = SIGTRAP;
   m_stop_info.details.fork.child_pid = child_pid;
   m_stop_info.details.fork.child_tid = child_pid;
 }
@@ -467,13 +468,14 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonVForkDone;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadLinux::SetStoppedWithNoReason() {
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonNone;
-  m_stop_info.details.signal.signo = 0;
+  m_stop_info.signo = 0;
 }
 
 void NativeThreadLinux::SetStoppedByProcessorTrace(
@@ -481,7 +483,7 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonProcessorTrace;
-  m_stop_info.details.signal.signo = 0;
+  m_stop_info.signo = 0;
   m_stop_description = description.str();
 }
 
diff --git a/lldb/source/Plugins/Process/NetBSD/NativeThreadNetBSD.cpp b/lldb/source/Plugins/Process/NetBSD/NativeThreadNetBSD.cpp
--- a/lldb/source/Plugins/Process/NetBSD/NativeThreadNetBSD.cpp
+++ b/lldb/source/Plugins/Process/NetBSD/NativeThreadNetBSD.cpp
@@ -81,7 +81,7 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonSignal;
-  m_stop_info.details.signal.signo = signo;
+  m_stop_info.signo = signo;
 
   m_stop_description.clear();
   if (info) {
@@ -100,19 +100,19 @@
 void NativeThreadNetBSD::SetStoppedByBreakpoint() {
   SetStopped();
   m_stop_info.reason = StopReason::eStopReasonBreakpoint;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadNetBSD::SetStoppedByTrace() {
   SetStopped();
   m_stop_info.reason = StopReason::eStopReasonTrace;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadNetBSD::SetStoppedByExec() {
   SetStopped();
   m_stop_info.reason = StopReason::eStopReasonExec;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadNetBSD::SetStoppedByWatchpoint(uint32_t wp_index) {
@@ -127,7 +127,7 @@
   SetStopped();
   m_stop_description = ostr.str();
   m_stop_info.reason = StopReason::eStopReasonWatchpoint;
-  m_stop_info.details.signal.signo = SIGTRAP;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadNetBSD::SetStoppedByFork(lldb::pid_t child_pid,
@@ -135,6 +135,7 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonFork;
+  m_stop_info.signo = SIGTRAP;
   m_stop_info.details.fork.child_pid = child_pid;
   m_stop_info.details.fork.child_tid = child_tid;
 }
@@ -144,6 +145,7 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonVFork;
+  m_stop_info.signo = SIGTRAP;
   m_stop_info.details.fork.child_pid = child_pid;
   m_stop_info.details.fork.child_tid = child_tid;
 }
@@ -152,13 +154,14 @@
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonVForkDone;
+  m_stop_info.signo = SIGTRAP;
 }
 
 void NativeThreadNetBSD::SetStoppedWithNoReason() {
   SetStopped();
 
   m_stop_info.reason = StopReason::eStopReasonNone;
-  m_stop_info.details.signal.signo = 0;
+  m_stop_info.signo = 0;
 }
 
 void NativeThreadNetBSD::SetStopped() {
diff --git a/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp b/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp
--- a/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp
+++ b/lldb/source/Plugins/Process/Windows/Common/NativeProcessWindows.cpp
@@ -253,13 +253,12 @@
 
   ThreadStopInfo stop_info;
   stop_info.reason = reason;
-
   // No signal support on Windows but required to provide a 'valid' signum.
+  stop_info.signo = SIGTRAP;
+
   if (reason == StopReason::eStopReasonException) {
     stop_info.details.exception.type = 0;
     stop_info.details.exception.data_count = 0;
-  } else {
-    stop_info.details.signal.signo = SIGTRAP;
   }
 
   thread.SetStopReason(stop_info, description);
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.cpp
@@ -728,7 +728,7 @@
       return llvm::make_error<llvm::StringError>(
           "failed to get stop reason", llvm::inconvertibleErrorCode());
 
-    const int signum = tid_stop_info.details.signal.signo;
+    const int signum = tid_stop_info.signo;
     if (log) {
       LLDB_LOGF(log,
                 "GDBRemoteCommunicationServerLLGS::%s pid %" PRIu64
@@ -804,7 +804,7 @@
 
   // Output the T packet with the thread
   response.PutChar('T');
-  int signum = tid_stop_info.details.signal.signo;
+  int signum = tid_stop_info.signo;
   LLDB_LOG(
       log,
       "pid {0}, tid {1}, got signal signo = {2}, reason = {3}, exc_type = {4}",
diff --git a/lldb/test/API/tools/lldb-server/TestGdbRemoteFork.py b/lldb/test/API/tools/lldb-server/TestGdbRemoteFork.py
--- a/lldb/test/API/tools/lldb-server/TestGdbRemoteFork.py
+++ b/lldb/test/API/tools/lldb-server/TestGdbRemoteFork.py
@@ -15,7 +15,7 @@
         self.reset_test_sequence()
 
         # continue and expect fork
-        fork_regex = "[$]T.*;fork:p([0-9a-f]+)[.]([0-9a-f]+).*"
+        fork_regex = "[$]T05.*;fork:p([0-9a-f]+)[.]([0-9a-f]+).*"
         self.test_sequence.add_log_lines([
             "read packet: $c#00",
             {"direction": "send", "regex": fork_regex,
@@ -49,7 +49,7 @@
         self.reset_test_sequence()
 
         # continue and expect fork
-        fork_regex = "[$]T.*;{}:p([0-9a-f]+)[.]([0-9a-f]+).*".format(variant)
+        fork_regex = "[$]T05.*;{}:p([0-9a-f]+)[.]([0-9a-f]+).*".format(variant)
         self.test_sequence.add_log_lines([
             "read packet: $c#00",
             {"direction": "send", "regex": fork_regex,
@@ -85,7 +85,7 @@
         # resume the parent
         self.test_sequence.add_log_lines([
             "read packet: $c#00",
-            {"direction": "send", "regex": r"[$]T.*vforkdone.*"},
+            {"direction": "send", "regex": r"[$]T05.*vforkdone.*"},
             "read packet: $c#00",
             {"direction": "send", "regex": r"[$]W00;process:[0-9a-f]+#.*"},
         ], True)
diff --git a/lldb/tools/debugserver/source/RNBRemote.cpp b/lldb/tools/debugserver/source/RNBRemote.cpp
--- a/lldb/tools/debugserver/source/RNBRemote.cpp
+++ b/lldb/tools/debugserver/source/RNBRemote.cpp
@@ -2704,7 +2704,7 @@
     std::ostringstream ostrm;
     // Output the T packet with the thread
     ostrm << 'T';
-    int signum = tid_stop_info.details.signal.signo;
+    int signum = tid_stop_info.signo;
     DNBLogThreadedIf(
         LOG_RNB_PROC, "%8d %s got signal signo = %u, exc_type = %u",
         (uint32_t)m_comm.Timer().ElapsedMicroSeconds(true), __FUNCTION__,
@@ -5450,9 +5450,9 @@
           break;
 
         case eStopTypeSignal:
-          if (tid_stop_info.details.signal.signo != 0) {
+          if (tid_stop_info.signo != 0) {
             thread_dict_sp->AddIntegerItem("signal",
-                                           tid_stop_info.details.signal.signo);
+                                           tid_stop_info.signo);
             reason_value = "signal";
           }
           break;