I think I fixed the import and export clipboard manual buttons. They work for me for now at least.

src/fenrirscreenreader/utils/x_clipboard.py

@@ -68,11 +68,14 @@ def _run_command(command, display, input_text=None):
     input_bytes = None
     if input_text is not None:
         input_bytes = input_text.encode(_ENCODING)
+    output_target = (
+        subprocess.PIPE if input_text is None else subprocess.DEVNULL
+    )
     return subprocess.run(
         command,
         input=input_bytes,
-        stdout=subprocess.PIPE,
+        stdout=output_target,
-        stderr=subprocess.PIPE,
+        stderr=output_target,
         env=_env_for_display(display),
         timeout=_CLIPBOARD_TIMEOUT,
         check=False,
@@ -80,7 +83,9 @@ def _run_command(command, display, input_text=None):
 
 
 def _command_error(command, result):
-    stderr = result.stderr.decode(_ENCODING, errors="replace").strip()
+    stderr = (result.stderr or b"").decode(
+        _ENCODING, errors="replace"
+    ).strip()
     if stderr:
         return RuntimeError(stderr)
     return RuntimeError(

tests/unit/test_x_clipboard.py

@@ -37,6 +37,25 @@ def test_write_text_uses_display_env_without_mutating_process_env(
     assert os.environ.get("DISPLAY") is None
 
 
+@pytest.mark.unit
+def test_write_text_does_not_capture_daemonized_writer_pipes(monkeypatch):
+    monkeypatch.setattr(x_clipboard.shutil, "which", command_exists)
+
+    def run_command(command, **kwargs):
+        if (
+            kwargs["stdout"] == subprocess.PIPE
+            or kwargs["stderr"] == subprocess.PIPE
+        ):
+            raise subprocess.TimeoutExpired(command, 2.0)
+        return subprocess.CompletedProcess(
+            command, 0, stdout=None, stderr=None
+        )
+
+    monkeypatch.setattr(x_clipboard.subprocess, "run", run_command)
+
+    assert x_clipboard.write_text("clipboard text", ":3") is True
+
+
 @pytest.mark.unit
 def test_read_text_scans_displays_until_text_is_found(monkeypatch):
     monkeypatch.delenv("DISPLAY", raising=False)