diff --git a/src/calibre/debug.py b/src/calibre/debug.py
index 24f727475b..0b4d2b252e 100644
--- a/src/calibre/debug.py
+++ b/src/calibre/debug.py
@@ -18,9 +18,10 @@ from polyglot.builtins import exec_path
 def run_calibre_debug(*args, **kw):
     import subprocess
     creationflags = 0
+    headless = bool(kw.pop('headless', False))
     if iswindows:
         creationflags = subprocess.CREATE_NO_WINDOW
-    cmd = get_debug_executable() + list(args)
+    cmd = get_debug_executable(headless=headless) + list(args)
     kw['creationflags'] = creationflags
     return subprocess.Popen(cmd, **kw)
 
diff --git a/src/calibre/startup.py b/src/calibre/startup.py
index 4e31a9c6af..32b4b6625d 100644
--- a/src/calibre/startup.py
+++ b/src/calibre/startup.py
@@ -22,10 +22,15 @@ builtins.__dict__['dynamic_property'] = lambda func: func(None)
 from calibre.constants import iswindows, ismacos, islinux, DEBUG, isfreebsd
 
 
-def get_debug_executable():
+def get_debug_executable(headless=False):
     exe_name = 'calibre-debug' + ('.exe' if iswindows else '')
     if hasattr(sys, 'frameworks_dir'):
         base = os.path.dirname(sys.frameworks_dir)
+        if headless:
+            from calibre.utils.ipc.launch import Worker
+            class W(Worker):
+                exe_name = 'calibre-debug'
+            return [W().executable]
         return [os.path.join(base, 'MacOS', exe_name)]
     if getattr(sys, 'run_local', None):
         return [sys.run_local, exe_name]
diff --git a/src/calibre/utils/ipc/launch.py b/src/calibre/utils/ipc/launch.py
index 7fdf1889df..ba81f92387 100644
--- a/src/calibre/utils/ipc/launch.py
+++ b/src/calibre/utils/ipc/launch.py
@@ -140,11 +140,10 @@ class Worker:
         except:
             pass
 
-    def __init__(self, env, gui=False, job_name=None):
-        self._env = {}
+    def __init__(self, env=None, gui=False, job_name=None):
         self.gui = gui
         self.job_name = job_name
-        self._env = env.copy()
+        self._env = (env or {}).copy()
 
     def __call__(self, redirect_output=True, cwd=None, priority=None, pass_fds=()):
         '''
diff --git a/src/calibre/utils/rapydscript.py b/src/calibre/utils/rapydscript.py
index 85f9842871..1933808ec2 100644
--- a/src/calibre/utils/rapydscript.py
+++ b/src/calibre/utils/rapydscript.py
@@ -233,7 +233,7 @@ def forked_compile():
 def run_forked_compile(data, options):
     from calibre.debug import run_calibre_debug
     p = run_calibre_debug('-c', 'from calibre.utils.rapydscript import *; forked_compile()',
-            json.dumps(options), stdin=subprocess.PIPE, stdout=subprocess.PIPE)
+            json.dumps(options), stdin=subprocess.PIPE, stdout=subprocess.PIPE, headless=True)
     stdout = p.communicate(as_bytes(data))[0]
     if p.wait() != 0:
         raise SystemExit(p.returncode)