TUI crash - MarkupError: closing tag '[/dim]' at position 52 doesn't match any open tag

[porthos-co]

Issue

It's probably something wrong in my configuration because I haven't seen anyone else reporting this, but whenever I use the TUI, I eventually, after probably twenty or thirty messages, run into this error and crash. So, my workaround has been using it in non-TUI mode, and I've found that this happens whether I use Claude 4.5, 4.6, Gemini 3, or Gemini 2 and a half as architect.

╭──────────────────────────────────────────────────────────── Traceback (most recent call last) ────────────────────────────────────────────────────────────╮
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/textual/worker.py:370 in _run │
│ │
│ 367 │ │ │ self.state = WorkerState.RUNNING │
│ 368 │ │ │ app.log.worker(self) │
│ 369 │ │ │ try: │
│ ❱ 370 │ │ │ │ self._result = await self.run() │
│ 371 │ │ │ except asyncio.CancelledError as error: │
│ 372 │ │ │ │ self.state = WorkerState.CANCELLED │
│ 373 │ │ │ │ self._error = error │
│ │
│ ╭───────────────────────────────────────────────────────────────── locals ──────────────────────────────────────────────────────────────────╮ │
│ │ app = TUI(title='TUI', classes={'-dark-mode'}, pseudo_classes={'dark', 'focus'}) │ │
│ │ error = MarkupError("closing tag '[/dim]' at position 52 doesn't match any open tag") │ │
│ │ self = │ │
│ │ worker_failed = WorkerFailed('Worker raised exception: MarkupError("closing tag '[/dim]' at position 52 doesn't match any open tag")') │ │
│ ╰───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/textual/worker.py:354 in run │
│ │
│ 351 │ │ Returns: │
│ 352 │ │ │ Return value of the work. │
│ 353 │ │ """ │
│ ❱ 354 │ │ return await ( │
│ 355 │ │ │ self._run_threaded() if self._thread_worker else self._run_async() │
│ 356 │ │ ) │
│ 357 │
│ │
│ ╭──────────────────────────────────────────────────── locals ─────────────────────────────────────────────────────╮ │
│ │ self = │ │
│ ╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/textual/worker.py:341 in _run_async │
│ │
│ 338 │ │ ): │
│ 339 │ │ │ return await self._work() │
│ 340 │ │ elif inspect.isawaitable(self._work): │
│ ❱ 341 │ │ │ return await self._work │
│ 342 │ │ elif callable(self._work): │
│ 343 │ │ │ raise WorkerError("Request to run a non-async function as an async worker") │
│ 344 │ │ raise WorkerError("Unsupported attempt to run an async worker") │
│ │
│ ╭──────────────────────────────────────────────────── locals ─────────────────────────────────────────────────────╮ │
│ │ self = │ │
│ ╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/cecli/tui/app.py:504 in _stream_chunk │
│ │
│ 501 │ async def _stream_chunk(self, text: str): │
│ 502 │ │ """Stream a chunk to the current response (async helper).""" │
│ 503 │ │ output_container = self.query_one("#output", OutputContainer) │
│ ❱ 504 │ │ await output_container.stream_chunk(text) │
│ 505 │ │
│ 506 │ async def _end_response(self): │
│ 507 │ │ """End the current LLM response (async helper).""" │
│ │
│ ╭─────────────────────────────────────────── locals ────────────────────────────────────────────╮ │
│ │ output_container = OutputContainer(id='output') │ │
│ │ self = TUI(title='TUI', classes={'-dark-mode'}, pseudo_classes={'dark', 'focus'}) │ │
│ │ text = '/dim]"\n )' │ │
│ ╰───────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/cecli/tui/widgets/output.py:114 in stream_chunk │
│ │
│ 111 │ │ │ │ # Output each wrapped line │
│ 112 │ │ │ │ for wrapped in wrapped_line.split("\n"): │
│ 113 │ │ │ │ │ if wrapped.strip(): │
│ ❱ 114 │ │ │ │ │ │ self.output(wrapped, render_markdown=True) │
│ 115 │ │
│ 116 │ async def end_response(self): │
│ 117 │ │ """End the current LLM response.""" │
│ │
│ ╭──────────────────────────────────── locals ────────────────────────────────────╮ │
│ │ line = ' f"{len(registry['conditions'])} conditions[/dim]"' │ │
│ │ self = OutputContainer(id='output') │ │
│ │ text = '/dim]"\n )' │ │
│ │ wrapped = ' f"{len(registry['conditions'])} conditions[/dim]"' │ │
│ │ wrapped_line = ' f"{len(registry['conditions'])} conditions[/dim]"' │ │
│ ╰────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/cecli/tui/widgets/output.py:321 in output │
│ │
│ 318 │ │ │ │ return │
│ 319 │ │ │
│ 320 │ │ # Call the actual write method │
│ ❱ 321 │ │ self.write(text) │
│ 322 │ │ │
│ 323 │ │ # Log the write using the plain text │
│ 324 │ │ self._write_history.append(plain_text) │
│ │
│ ╭────────────────────────────────────── locals ──────────────────────────────────────╮ │
│ │ check_duplicates = True │ │
│ │ nl_check = False │ │
│ │ nl_last = False │ │
│ │ nl_penultimate = False │ │
│ │ plain_text = ' f"{len(registry['conditions'])} conditions[/dim]"' │ │
│ │ render_markdown = True │ │
│ │ self = OutputContainer(id='output') │ │
│ │ text = ' f"{len(registry['conditions'])} conditions[/dim]"' │ │
│ ╰────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/textual/widgets/_rich_log.py:215 in write │
│ │
│ 212 │ │ │ ) │
│ 213 │ │ │ return self │
│ 214 │ │ │
│ ❱ 215 │ │ renderable = self._make_renderable(content) │
│ 216 │ │ auto_scroll = self.auto_scroll if scroll_end is None else scroll_end │
│ 217 │ │ │
│ 218 │ │ console = self.app.console │
│ │
│ ╭─────────────────────────────────── locals ───────────────────────────────────╮ │
│ │ animate = False │ │
│ │ content = ' f"{len(registry['conditions'])} conditions[/dim]"' │ │
│ │ expand = False │ │
│ │ scroll_end = None │ │
│ │ self = OutputContainer(id='output') │ │
│ │ shrink = True │ │
│ │ width = None │ │
│ ╰──────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/textual/widgets/_rich_log.py:162 in _make_renderable │
│ │
│ 159 │ │ else: │
│ 160 │ │ │ if isinstance(content, str): │
│ 161 │ │ │ │ if self.markup: │
│ ❱ 162 │ │ │ │ │ renderable = Text.from_markup(content) │
│ 163 │ │ │ │ else: │
│ 164 │ │ │ │ │ renderable = Text(content) │
│ 165 │ │ │ │ if self.highlight: │
│ │
│ ╭───────────────────────────────── locals ──────────────────────────────────╮ │
│ │ content = ' f"{len(registry['conditions'])} conditions[/dim]"' │ │
│ │ self = OutputContainer(id='output') │ │
│ ╰───────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/rich/text.py:287 in from_markup │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/rich/markup.py:167 in render │
╰───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
MarkupError: closing tag '[/dim]' at position 52 doesn't match any open tag

Version and model info

Model: anthropic/claude-opus-4-6, Edit format: architect
Loaded 55 messages and 8 files
cecli v0.97.2
Main model: anthropic/claude-opus-4-6 with architect edit format
Editor model: vertex_ai/gemini-2.5-pro with editor-diff-fenced edit format
Weak model: vertex_ai/gemini-2.5-pro
Git repo: .git with 57 files
Repo-map: using 4096 tokens, files refresh

---

~/.cecli.conf.yml

architect: true
model: anthropic/claude-opus-4-6
editor-model: vertex_ai/gemini-2.5-pro
weak-model: vertex_ai/gemini-2.5-pro

alias:

ARCHITECT: Max Effort (The "Deep Thinker" for planning)

• "c4.6-max:anthropic/claude-opus-4-6"

RESEARCHER: High Effort (The Default for complex logic)

• "c4.6-high:anthropic/claude-opus-4-6"

DEV: Medium Effort (Balanced speed/cost for daily work)

• "c4.6-mid:anthropic/claude-opus-4-6"

Standard Gemini Aliases

• "g2.5p:vertex_ai/gemini-2.5-pro"

check-model-accepts-settings: false
show-model-warnings: true

--- History & Context ---

check-update: false
debug: true
watch-files: false
auto-commits: true
auto-save: true
auto-load: true
use-enhanced-map: true
cache-prompts: true
enable-context-compaction: true
context-compaction-max-tokens: 64000
editor: nvim
multiline: true

--- Interface ---

tui: true
vim: false
tui-config:
colors:
primary: "#00ff5f"
secondary: "#888888"
accent: "#00ff87"
foreground: "#ffffff"
background: "hsl(315,100%,6%)"
success: "#00aa00"
warning: "#ffd700"
error: "#ff3333"
surface: "transparent"
panel: "transparent"
input-cursor-foreground: "#00ff87"
other:
dark: true
input-cursor-text-style: "underline"
key_bindings:
newline: "shift+enter"
submit: "enter"
completion: "tab"
stop: "escape"
editor: "ctrl+o"
history: "ctrl+r"
cycle_forward: "tab"
cycle_backward: "shift+tab"
focus: "ctrl+f"
cancel: "ctrl+c"
clear: "ctrl+l"
quit: "ctrl+q"

--- TUI ----

mcp-servers:
mcpServers: {}

--- File Management ---

env-file: ~/.cecli.env

#--- READ-ONLY FILES ---
read:

• .cecli_rules.md
• .cecli_project_rules.md

[dwash96]

Hmm, definitely some sort of parser error in Rich's output. I've never seen this before but I will look into this. I wonder what the model would have to generate to break this 🤔

[dwash96]

Alright, I know why this happens, but just curious, you're building a terminal utility/application with Rich?

[porthos-co]

Yes, that's partly right. It's basically AI Google for mortgage lending criteria in the UK. So will be used by brokers and advisors and it's looking pretty amazing. They use a web-based and partly chat-based front end. And the backend is a Neo4j database and Python/ LLM layer / DSPy etc.

So doing that requires indexing and chunking a hell of a lot of data, and so for the admin interface I'm using Rich and textual. It's much quicker and easier to deal with than a separate admin web front-end. Inspired by you! As they say, copying is the sincerest form of flattery.... ;-)

[dwash96]

Haha, well that's awesome man, I'll push 0.97.3 tonight and this should stop being an obstruction for ya!

[porthos-co]

You are amazingly kind, and huge thanks as ever for all your hard work.

[porthos-co]

So I thought this was fixed, and I've been testing quite heavily the last couple of days, but I've just hit it a couple of times again.

I've slightly clipped these output messages and tracebacks. And the output code here that I'm working on will involve rich in this case but not textual, so I'm wondering whether this is because I'm using Gemini 2.5 as an editor and it's doing something weird. It always seems to happen when edits are happening, particularly when an edit has been misapplied.

---

cecli
Starting cecli TUI...
╭─────────────────────────────────────────────────────────────────────────── Traceback (most recent call last) ───────────────────────────────────────────────────────────────────────────╮
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/cecli/tui/app.py:438 in check_output_queue │
│ │
│ 435 │ │ try: │
│ 436 │ │ │ while True: │
│ 437 │ │ │ │ msg = self.output_queue.get_nowait() │
│ ❱ 438 │ │ │ │ self.handle_output_message(msg) │
│ 439 │ │ except queue.Empty: │
│ 440 │ │ │ pass │
│ 441 │
│ │
│ ╭──────────────────────────────────────────────────────────────────── locals ────────────────────────────────────────────────────────────────────╮ │
│ │ msg = {'type': 'output', 'text': '# 2 SEARCH/REPLACE blocks failed to match!\n\n## SearchReplaceNoExactMatch: This S'+16693, 'task_id': None} │ │
│ │ self = TUI(title='TUI', classes={'-dark-mode'}, pseudo_classes={'focus', 'dark'}) │ │
│ ╰────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/cecli/tui/app.py:447 in handle_output_message │
│ │
│ 444 │ │ msg_type = msg["type"] │
│ 445 │ │ │
│ 446 │ │ if msg_type == "output": │
│ ❱ 447 │ │ │ self.add_output(msg["text"], msg.get("task_id")) │
│ 448 │ │ elif msg_type == "tool_call": │
│ 449 │ │ │ # Render tool call with styled panel │
│ 450 │ │ │ output_container = self.query_one("#output", OutputContainer) │
│ │
│ ╭────────────────────────────────────────────────────────────────────── locals ──────────────────────────────────────────────────────────────────────╮ │
│ │ msg = {'type': 'output', 'text': '# 2 SEARCH/REPLACE blocks failed to match!\n\n## SearchReplaceNoExactMatch: This S'+16693, 'task_id': None} │ │
│ │ msg_type = 'output' │ │
│ │ self = TUI(title='TUI', classes={'-dark-mode'}, pseudo_classes={'focus', 'dark'}) │ │
│ ╰────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/cecli/tui/app.py:494 in add_output │
│ │
│ 491 │ def add_output(self, text, task_id=None): │
│ 492 │ │ """Add output to the output container.""" │
│ 493 │ │ output_container = self.query_one("#output", OutputContainer) │
│ ❱ 494 │ │ output_container.add_output(text, task_id) │
│ 495 │ │
│ 496 │ async def _start_response(self): │
│ 497 │ │ """Start a new LLM response (async helper).""" │
│ │
│ ╭─────────────────────────────────────────────────── locals ────────────────────────────────────────────────────╮ │
│ │ output_container = OutputContainer(id='output') │ │
│ │ self = TUI(title='TUI', classes={'-dark-mode'}, pseudo_classes={'focus', 'dark'}) │ │
│ │ task_id = None │ │
│ │ text = '# 2 SEARCH/REPLACE blocks failed to match!\n\n## SearchReplaceNoExactMatch: This S'+16693 │ │
│ ╰───────────────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/cecli/tui/widgets/output.py:197 in add_output │
│ │
│ 194 │ │ │
│ 195 │ │ # Always treat add_output as system messages │
│ 196 │ │ # LLM streaming goes through the dedicated stream_chunk path │
│ ❱ 197 │ │ self.add_system_message(text, dim=dim) │
│ 198 │ │
│ 199 │ def add_output_styled(self, text: str, styles=None): │
│ 200 │ │ if not styles: │
│ │
│ ╭─────────────────────────────────────────────── locals ───────────────────────────────────────────────╮ │
│ │ dim = True │ │
│ │ self = OutputContainer(id='output') │ │
│ │ task_id = None │ │
│ │ text = '# 2 SEARCH/REPLACE blocks failed to match!\n\n## SearchReplaceNoExactMatch: This S'+16693 │ │
│ ╰──────────────────────────────────────────────────────────────────────────────────────────────────────╯ │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/cecli/tui/widgets/output.py:181 in add_system_message │
│ │
│ 178 │ │ │ text = Padding(f"{start}{text}{end}", (0, 0, 0, 2)) │
│ 179 │ │ │
│ 180 │ │ self.set_last_write_type("system") │
│ ❱ 181 │ │ self.output(text) │
│ 182 │ │
│ 183 │ def add_output(self, text: str, task_id: str = None, dim=True): │
│ 184 │ │ """Add output text as a system message. │
│

[CLIPPED]

/home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/rich/measure.py:144 in measure_renderables │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/rich/measure.py:145 in │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/rich/measure.py:109 in get │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/rich/padding.py:132 in rich_measure │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/rich/measure.py:99 in get │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/rich/console.py:1448 in render_str │
│ │
│ /home/sa_110454126533284998741/.local/share/pipx/venvs/cecli-dev/lib/python3.11/site-packages/rich/markup.py:174 in render │
╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
MarkupError: closing tag '[/]' at position 1831 has nothing to close