diff --git a/.github/workflows/commit-tests.yml b/.github/workflows/commit-tests.yml
index c2aea1dc8ec50..58c35a0a5ce1c 100644
--- a/.github/workflows/commit-tests.yml
+++ b/.github/workflows/commit-tests.yml
@@ -3,7 +3,11 @@ name: Commit Tests
 env:
   release_major: 9
 
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - 'release/**'
+  pull_request:
 
 jobs:
   build_llvm:
@@ -44,8 +48,10 @@ jobs:
             # FIXME: Referencing the env context does not work here
             # ref: llvmorg-${{ env.release_major }}.0.0
             ref: llvmorg-9.0.0
+            repo: llvm/llvm-project
           - name: build-latest
             ref: ${{ github.sha }}
+            repo: ${{ github.repository }}
     steps:
     - name: Install Ninja
       uses: llvm/actions/install-ninja@master
@@ -55,6 +61,7 @@ jobs:
       uses: llvm/actions/get-llvm-project-src@master
       with:
         ref: ${{ matrix.ref }}
+        repo: ${{ matrix.repo }}
     - name: Configure
       run: |
         mkdir build
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/CMakeLists.txt b/lldb/source/Plugins/ScriptInterpreter/Python/CMakeLists.txt
index f7360d7288919..915f07e2ca6a7 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/CMakeLists.txt
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/CMakeLists.txt
@@ -14,6 +14,7 @@ endif()
 add_lldb_library(lldbPluginScriptInterpreterPython PLUGIN
   PythonDataObjects.cpp
   PythonExceptionState.cpp
+  PythonReadline.cpp
   ScriptInterpreterPython.cpp
 
   LINK_LIBS
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.cpp
new file mode 100644
index 0000000000000..616522f9de905
--- /dev/null
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.cpp
@@ -0,0 +1,80 @@
+#include "PythonReadline.h"
+
+#ifdef LLDB_USE_LIBEDIT_READLINE_COMPAT_MODULE
+
+#include <stdio.h>
+
+#include <editline/readline.h>
+
+// Simple implementation of the Python readline module using libedit.
+// In the event that libedit is excluded from the build, this turns
+// back into a null implementation that blocks the module from pulling
+// in the GNU readline shared lib, which causes linkage confusion when
+// both readline and libedit's readline compatibility symbols collide.
+//
+// Currently it only installs a PyOS_ReadlineFunctionPointer, without
+// implementing any of the readline module methods. This is meant to
+// work around LLVM pr18841 to avoid seg faults in the stock Python
+// readline.so linked against GNU readline.
+//
+// Bug on the cpython side: https://bugs.python.org/issue38634
+
+PyDoc_STRVAR(moduleDocumentation,
+             "Simple readline module implementation based on libedit.");
+
+#if PY_MAJOR_VERSION >= 3
+static struct PyModuleDef readline_module = {
+    PyModuleDef_HEAD_INIT, // m_base
+    "lldb_editline",       // m_name
+    moduleDocumentation,   // m_doc
+    -1,                    // m_size
+    nullptr,               // m_methods
+    nullptr,               // m_reload
+    nullptr,               // m_traverse
+    nullptr,               // m_clear
+    nullptr,               // m_free
+};
+#else
+static struct PyMethodDef moduleMethods[] = {{nullptr, nullptr, 0, nullptr}};
+#endif
+
+static char *
+#if PY_MAJOR_VERSION >= 3
+simple_readline(FILE *stdin, FILE *stdout, const char *prompt)
+#else
+simple_readline(FILE *stdin, FILE *stdout, char *prompt)
+#endif
+{
+  rl_instream = stdin;
+  rl_outstream = stdout;
+  char *line = readline(prompt);
+  if (!line) {
+    char *ret = (char *)PyMem_RawMalloc(1);
+    if (ret != NULL)
+      *ret = '\0';
+    return ret;
+  }
+  if (*line)
+    add_history(line);
+  int n = strlen(line);
+  char *ret = (char *)PyMem_RawMalloc(n + 2);
+  if (ret) {
+    strncpy(ret, line, n);
+    free(line);
+    ret[n] = '\n';
+    ret[n + 1] = '\0';
+  }
+  return ret;
+}
+
+PyMODINIT_FUNC initlldb_readline(void) {
+  PyOS_ReadlineFunctionPointer = simple_readline;
+
+#if PY_MAJOR_VERSION >= 3
+  return PyModule_Create(&readline_module);
+#else
+  Py_InitModule4("lldb_readline", moduleMethods, moduleDocumentation,
+                 static_cast<PyObject *>(NULL), PYTHON_API_VERSION);
+#endif
+}
+#endif
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.h b/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.h
new file mode 100644
index 0000000000000..faf95bb64486d
--- /dev/null
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/PythonReadline.h
@@ -0,0 +1,26 @@
+//===-- PythonReadline.h ----------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_PYTHONREADLINE_H
+#define LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_PYTHONREADLINE_H
+
+#if !defined(LLDB_DISABLE_LIBEDIT) && defined(__linux__)
+// NOTE: Since Python may define some pre-processor definitions which affect the
+// standard headers on some systems, you must include Python.h before any
+// standard headers are included.
+#include "Python.h"
+
+// no need to hack into Python's readline module if libedit isn't used.
+//
+#define LLDB_USE_LIBEDIT_READLINE_COMPAT_MODULE 1
+
+extern "C" PyMODINIT_FUNC initlldb_readline(void);
+
+#endif
+
+#endif // LLDB_PLUGINS_SCRIPTINTERPRETER_PYTHON_PYTHONREADLINE_H
diff --git a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
index 2d2b68ceaaa6b..e470dfeab98cf 100644
--- a/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
+++ b/lldb/source/Plugins/ScriptInterpreter/Python/ScriptInterpreterPython.cpp
@@ -17,6 +17,7 @@
 
 #include "PythonDataObjects.h"
 #include "PythonExceptionState.h"
+#include "PythonReadline.h"
 #include "ScriptInterpreterPythonImpl.h"
 
 #include "lldb/API/SBFrame.h"
@@ -207,6 +208,22 @@ struct InitializePythonRAII {
 
     InitializePythonHome();
 
+#ifdef LLDB_USE_LIBEDIT_READLINE_COMPAT_MODULE
+    // Python's readline is incompatible with libedit being linked into lldb.
+    // Provide a patched version local to the embedded interpreter.
+    bool ReadlinePatched = false;
+    for (auto *p = PyImport_Inittab; p->name != NULL; p++) {
+      if (strcmp(p->name, "readline") == 0) {
+        p->initfunc = initlldb_readline;
+        break;
+      }
+    }
+    if (!ReadlinePatched) {
+      PyImport_AppendInittab("readline", initlldb_readline);
+      ReadlinePatched = true;
+    }
+#endif
+
     // Register _lldb as a built-in module.
     PyImport_AppendInittab("_lldb", LLDBSwigPyInit);