Index: lldb/source/Target/Process.cpp
===================================================================
--- lldb/source/Target/Process.cpp
+++ lldb/source/Target/Process.cpp
@@ -65,6 +65,7 @@
 #include "lldb/Utility/Log.h"
 #include "lldb/Utility/NameMatches.h"
 #include "lldb/Utility/ProcessInfo.h"
+#include "lldb/Utility/Reproducer.h"
 #include "lldb/Utility/SelectHelper.h"
 #include "lldb/Utility/State.h"
 
@@ -2790,6 +2791,11 @@
           }
           return error;
         }
+      } else if (repro::Reproducer::Instance().IsReplaying()) {
+        // The actual PID doesn't matter, we just need to set it to something
+        // that's not LLDB_INVALID_PROCESS_ID. The GDB remote replay
+        // infrastructure will intercept our attach later on.
+        attach_pid = 1;
       } else {
         ProcessInstanceInfoList process_infos;
         PlatformSP platform_sp(GetTarget().GetPlatform());
Index: lldb/test/Shell/Reproducer/Inputs/sleep.c
===================================================================
--- /dev/null
+++ lldb/test/Shell/Reproducer/Inputs/sleep.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+#include <unistd.h>
+
+int main(int argc, char const *argv[]) {
+  sleep(10);
+  return 0;
+}
Index: lldb/test/Shell/Reproducer/TestAttach.test
===================================================================
--- /dev/null
+++ lldb/test/Shell/Reproducer/TestAttach.test
@@ -0,0 +1,11 @@
+# UNSUPPORTED: system-windows, system-freebsd
+
+# RUN: rm -rf %t.repro
+# RUN: mkdir -p %t
+
+# RUN: %clang_host %S/Inputs/sleep.c -g -o %t/attach.out
+# RUN: python -c 'import os; os.system("%t/attach.out &")'
+
+# RUN: %lldb --capture --capture-path %t.repro -o 'pro att -n attach.out' -o 'reproducer generate' | FileCheck %s
+# RUN: %lldb --replay %t.repro | FileCheck %s
+# CHECK: stop reason = signal SIGSTOP