# Cursor Chat: ai-agent-book

## Metadata
- **Project**: ai-agent-book
- **Path**: `/Users/boj`
- **Date**: 2025-10-03 19:03:41
- **Session ID**: `98952224-44d5-4066-896d-c572b76817e6`

## Conversation

### 👤 You

File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/transformers/models/mistral/modeling_mistral.py", line 17, in <module>
    from ...modeling_flash_attention_utils import FlashAttentionKwargs
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/transformers/modeling_flash_attention_utils.py", line 36, in <module>
    from flash_attn.bert_padding import index_first_axis, pad_input, unpad_input  # noqa
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/flash_attn/__init__.py", line 3, in <module>
    from flash_attn.flash_attn_interface import (
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/flash_attn/flash_attn_interface.py", line 15, in <module>
    import flash_attn_2_cuda as flash_attn_gpu
ImportError: /root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/flash_attn_2_cuda.cpython-310-x86_64-linux-gnu.so: undefined symbol: _ZN3c105ErrorC2ENS_14SourceLocationENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/runpy.py", line 196, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "/root/AdaptThink/src/main_ppo.py", line 17, in <module>
    from .adapt_think_ray_trainer import AdaptThinkRayPPOTrainer
  File "/root/AdaptThink/src/adapt_think_ray_trainer.py", line 31, in <module>
    from verl.trainer.ppo.ray_trainer import RayPPOTrainer, _timer, apply_kl_penalty, compute_response_mask, AdvantageEstimator
  File "/root/AdaptThink/verl/trainer/ppo/ray_trainer.py", line 45, in <module>
    from verl.utils.dataset.rl_dataset import RLHFDataset, collate_fn
  File "/root/AdaptThink/verl/utils/dataset/__init__.py", line 15, in <module>
    from .rl_dataset import RLHFDataset
  File "/root/AdaptThink/verl/utils/dataset/rl_dataset.py", line 27, in <module>
    from verl.utils.model import compute_position_id_with_mask
  File "/root/AdaptThink/verl/utils/model.py", line 24, in <module>
    from transformers import AutoConfig, AutoModelForCausalLM, PretrainedConfig, MistralForSequenceClassification, GenerationConfig
  File "<frozen importlib._bootstrap>", line 1075, in _handle_fromlist
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/transformers/utils/import_utils.py", line 1956, in __getattr__
    value = getattr(module, name)
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/transformers/utils/import_utils.py", line 1955, in __getattr__
    module = self._get_module(self._class_to_module[name])
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/transformers/utils/import_utils.py", line 1969, in _get_module
    raise RuntimeError(
RuntimeError: Failed to import transformers.models.mistral.modeling_mistral because of the following error (look up to see its traceback):
/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/flash_attn_2_cuda.cpython-310-x86_64-linux-gnu.so: undefined symbol: _ZN3c105ErrorC2ENS_14SourceLocationENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE

--
How to fix the flash_attn link error?

---

### 🤖 Cursor Assistant

Looking at this Flash Attention import error, this is a common C++ ABI compatibility issue where `flash-attn` was compiled against a different version of PyTorch than what's currently installed.

Let me check the current requirements to understand the setup:

---

### 🤖 Cursor Assistant

The issue is that `flash-attn` was compiled against a different PyTorch version than what's currently installed. Here are several solutions:

## Solution 1: Reinstall flash-attn (Recommended)

Rebuild flash-attn to match your current PyTorch/CUDA environment:

```bash
# Uninstall existing flash-attn
pip uninstall flash-attn -y

# Reinstall flash-attn with no cache (forces recompilation)
pip install flash-attn --no-build-isolation --no-cache-dir
```

## Solution 2: Use Pre-built Wheels

If compilation is slow or problematic, use pre-built wheels:

```bash
pip uninstall flash-attn -y

# For PyTorch 2.1+ with CUDA 11.8
pip install flash-attn --no-build-isolation

# Or specify a compatible version explicitly
pip install flash-attn==2.5.8 --no-build-isolation
```

## Solution 3: Disable Flash Attention

If you don't need Flash Attention optimization, disable it:

```python
# Set environment variable before imports
import os
os.environ["TRANSFORMERS_NO_FLASH_ATTN"] = "1"
```

Or run with:
```bash
TRANSFORMERS_NO_FLASH_ATTN=1 python -m src.main_ppo
```

## Solution 4: Full Environment Rebuild

If the issue persists, reinstall PyTorch and flash-attn together:

```bash
# Check your CUDA version first
nvidia-smi

# Reinstall PyTorch (example for CUDA 11.8)
pip uninstall torch torchvision torchaudio -y
pip install torch torchvision torchaudio --index-url https://download.pytorch.org/whl/cu118

# Then reinstall flash-attn
pip uninstall flash-attn -y
pip install flash-attn --no-build-isolation --no-cache-dir
```

## Quick Fix to Test

The fastest way to verify the rest of your code works is to disable Flash Attention temporarily:

```bash
TRANSFORMERS_NO_FLASH_ATTN=1 python -m src.main_ppo [your args]
```

**Recommendation**: Start with Solution 1 (reinstalling flash-attn). This usually resolves the ABI mismatch without requiring a full environment rebuild.

---

### 👤 You

I'm using pytorch 2.6.0. Which flash attention version is ok? I tried solution 1, still not work

---

### 🤖 Cursor Assistant

Based on the research, for **PyTorch 2.6.0**, you should use **flash-attn 2.6.3** or **2.7.0+**. Here's the solution:

## Recommended Solution for PyTorch 2.6.0

```bash
# First, ensure ninja is installed (speeds up compilation)
pip install ninja

# Uninstall any existing flash-attn
pip uninstall flash-attn -y

# Install flash-attn 2.6.3 (confirmed compatible with PyTorch 2.6.0)
pip install flash-attn==2.6.3 --no-build-isolation --no-cache-dir
```

## If That Still Doesn't Work

Try the latest version:

```bash
pip uninstall flash-attn -y
pip install flash-attn==2.7.0 --no-build-isolation --no-cache-dir
```

## If Compilation Fails (Memory Issues)

Limit parallel jobs during compilation:

```bash
pip uninstall flash-attn -y
MAX_JOBS=4 pip install flash-attn==2.6.3 --no-build-isolation --no-cache-dir
```

## Verify Installation

After installation, test it:

```python
import torch
print(f"PyTorch version: {torch.__version__}")
print(f"CUDA available: {torch.cuda.is_available()}")

# Test flash attention import
try:
    from flash_attn import flash_attn_func
    print("✓ Flash Attention imported successfully")
except Exception as e:
    print(f"✗ Flash Attention import failed: {e}")
```

## Alternative: Use Pre-built Wheels

If compilation continues to fail, use pre-built wheels from this repo:

```bash
# Visit: https://github.com/Dao-AILab/flash-attention/releases
# Or use: https://github.com/mjun0812/flash-attention-prebuild-wheels

# Example for PyTorch 2.6.0 + CUDA 12.1:
pip install https://github.com/Dao-AILab/flash-attention/releases/download/v2.6.3/flash_attn-2.6.3+cu121torch2.6cxx11abiFALSE-cp310-cp310-linux_x86_64.whl
```

**Key Point**: The `_ZN3c105ErrorC2E` symbol error indicates the flash-attn binary was compiled with a different C++ ABI than your current PyTorch. Reinstalling with `--no-build-isolation --no-cache-dir` ensures it compiles against your current PyTorch installation.

Which CUDA version are you using? I can provide more specific guidance based on that.

---

### 👤 You

Traceback (most recent call last):
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/runpy.py", line 196, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/runpy.py", line 86, in _run_code
    exec(code, run_globals)
  File "/root/AdaptThink/src/main_ppo.py", line 17, in <module>
    from .adapt_think_ray_trainer import AdaptThinkRayPPOTrainer
  File "/root/AdaptThink/src/adapt_think_ray_trainer.py", line 31, in <module>
    from verl.trainer.ppo.ray_trainer import RayPPOTrainer, _timer, apply_kl_penalty, compute_response_mask, AdvantageEstimator
  File "/root/AdaptThink/verl/trainer/ppo/ray_trainer.py", line 45, in <module>
    from verl.utils.dataset.rl_dataset import RLHFDataset, collate_fn
  File "/root/AdaptThink/verl/utils/dataset/__init__.py", line 15, in <module>
    from .rl_dataset import RLHFDataset
  File "/root/AdaptThink/verl/utils/dataset/rl_dataset.py", line 27, in <module>
    from verl.utils.model import compute_position_id_with_mask
  File "/root/AdaptThink/verl/utils/model.py", line 24, in <module>
    from transformers import AutoConfig, AutoModelForCausalLM, PretrainedConfig, MistralForSequenceClassification, GenerationConfig
  File "<frozen importlib._bootstrap>", line 1075, in _handle_fromlist
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/transformers/utils/import_utils.py", line 1956, in __getattr__
    value = getattr(module, name)
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/transformers/utils/import_utils.py", line 1955, in __getattr__
    module = self._get_module(self._class_to_module[name])
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/transformers/utils/import_utils.py", line 1969, in _get_module
    raise RuntimeError(
RuntimeError: Failed to import transformers.models.mistral.modeling_mistral because of the following error (look up to see its traceback):
/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/flash_attn_2_cuda.cpython-310-x86_64-linux-gnu.so: undefined symbol: _ZN3c105ErrorC2ENS_14SourceLocationENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE

--
~/AdaptThink$ python
Python 3.10.18 (main, Jun  5 2025, 13:14:17) [GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> print(f"CUDA available: {torch.cuda.is_available()}")
KeyboardInterrupt
>>> import torch

>>> print(f"PyTorch version: {torch.__version__}")
PyTorch version: 2.6.0+cu124
>>> print(f"CUDA available: {torch.cuda.is_available()}")
CUDA available: True
>>> from flash_attn import flash_attn_func
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/flash_attn/__init__.py", line 3, in <module>
    from flash_attn.flash_attn_interface import (
  File "/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/flash_attn/flash_attn_interface.py", line 15, in <module>
    import flash_attn_2_cuda as flash_attn_gpu
ImportError: /root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/flash_attn_2_cuda.cpython-310-x86_64-linux-gnu.so: undefined symbol: _ZN3c105ErrorC2ENS_14SourceLocationENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE

---

### 🤖 Cursor Assistant

Good, you have **PyTorch 2.6.0+cu124** (CUDA 12.4). The issue persists because the flash-attn binary is still mismatched. Here's a comprehensive fix:

## Step 1: Clean Everything

```bash
# Remove all flash-attn related packages
pip uninstall flash-attn -y
pip uninstall flash-attn-interface -y

# Clean pip cache
pip cache purge

# Remove any cached builds
rm -rf ~/.cache/torch_extensions/
rm -rf /root/.cache/torch_extensions/
```

## Step 2: Verify PyTorch Installation

```bash
python -c "import torch; print(f'PyTorch: {torch.__version__}'); print(f'CUDA: {torch.version.cuda}'); print(f'CXX11 ABI: {torch._C._GLIBCXX_USE_CXX11_ABI}')"
```

This will show if PyTorch was compiled with the old or new C++ ABI.

## Step 3: Rebuild Flash Attention from Source

```bash
# Install build dependencies
pip install ninja packaging wheel

# Build from source (this may take 5-10 minutes)
pip install flash-attn==2.6.3 --no-build-isolation --no-cache-dir --force-reinstall
```

## Step 4: If Still Failing - Use Pre-built Wheel

For PyTorch 2.6.0 + CUDA 12.4, download the exact matching wheel:

```bash
# Try the pre-built wheel matching your exact setup
pip install https://github.com/Dao-AILab/flash-attention/releases/download/v2.6.3/flash_attn-2.6.3+cu124torch2.6cxx11abiFALSE-cp310-cp310-linux_x86_64.whl
```

If that URL doesn't work, check the [Flash Attention releases page](https://github.com/Dao-AILab/flash-attention/releases) for the exact wheel matching:
- Python 3.10
- PyTorch 2.6.0
- CUDA 12.4
- cxx11abiFALSE (or TRUE, depending on your PyTorch's ABI)

## Step 5: Alternative - Downgrade Transformers or Disable Flash Attention

If nothing works, you have two options:

**Option A: Disable Flash Attention Globally**

Add this to your code before any transformers imports (e.g., in `src/main_ppo.py` at the very top):

```python
import os
os.environ["TRANSFORMERS_NO_FLASH_ATTN"] = "1"
```

Or run with:
```bash
TRANSFORMERS_NO_FLASH_ATTN=1 python -m src.main_ppo
```

**Option B: Use a Different Attention Implementation**

Modify the model loading to explicitly disable flash attention:

```python
from transformers import AutoModelForCausalLM

model = AutoModelForCausalLM.from_pretrained(
    model_name,
    attn_implementation="sdpa"  # Use PyTorch's scaled_dot_product_attention instead
)
```

## Debugging: Check for Multiple PyTorch Installations

```bash
pip list | grep torch
conda list | grep torch
```

If you see multiple torch installations, that could be the issue. Clean them up and reinstall.

## Most Likely Solution

Given that rebuilding didn't work, I suspect the **pre-built wheel** approach (Step 4) or **disabling flash attention** (Step 5) will be your fastest path forward. The performance difference without flash attention is not dramatic for most use cases, especially during development.

Would you like me to help you implement the disable option as a temporary workaround while you sort out the flash-attn installation?

---

### 👤 You

$ python -c "import torch; print(f'PyTorch: {torch.__version__}'); print(f'CUDA: {torch.version.cuda}'); print(f'CXX11 ABI: {torch._C._GLIBCXX_USE_CXX11_ABI}')"
PyTorch: 2.6.0+cu124
CUDA: 12.4
CXX11 ABI: False

There is:

pip install https://github.com/Dao-AILab/flash-attention/releases/download/v2.8.3/flash_attn-2.8.3+cu12torch2.6cxx11abiFALSE-cp310-cp310-linux_x86_64.whl

But there is not 
pip install https://github.com/Dao-AILab/flash-attention/releases/download/v2.8.3/flash_attn-2.8.3+cu124torch2.6cxx11abiFALSE-cp310-cp310-linux_x86_64.whl

But after installing it, still shows error:
/root/miniconda3/envs/adapt_think/lib/python3.10/site-packages/flash_attn_2_cuda.cpython-310-x86_64-linux-gnu.so: undefined symbol: _ZN3c105ErrorC2ENS_14SourceLocationENSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE

---

### 🤖 Cursor Assistant

Perfect! You found the right wheel. The `cu12` designation covers **all CUDA 12.x versions** including your CUDA 12.4. This is the correct wheel for your setup.

Let me help you install it:

---

### 🤖 Cursor Assistant

Perfect! You have **CXX11 ABI: False**, which matches the wheel you tried. The fact that it still fails suggests there's a deeper compatibility issue between your PyTorch build and the flash-attn binaries.

At this point, the most practical solution is to **disable flash attention**. Here's how:

## Quick Fix: Disable Flash Attention

Since you're getting the error when importing transformers models, add this environment variable before running:

```bash
export TRANSFORMERS_NO_FLASH_ATTN=1
python -m src.main_ppo
```

Or make it permanent by adding it to the top of your main file:

---

### 🤖 Cursor Assistant

Perfect! I've added the fix to disable flash attention at the top of `main_ppo.py`. Now let's check if there are other

---

### 👤 You

ray.exceptions.RayTaskError(NotImplementedError): ray::TaskRunner.run() (pid=116729, ip=172.17.0.2, actor_id=3f02c8c6c801c1763452596101000000, repr=<main_ppo.TaskRunner object at 0x7ef31061b0e0>)
  File "/root/AdaptThink/src/main_ppo.py", line 182, in run
    trainer.fit()
    ~~~~~~~~~~~^^
  File "/root/AdaptThink/src/adapt_think_ray_trainer.py", line 356, in fit
    old_log_prob = self.actor_rollout_wg.compute_log_prob(batch)
  File "/root/AdaptThink/verl/single_controller/ray/base.py", line 43, in func
    output = ray.get(output)
                                  ~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
ray.exceptions.RayTaskError(NotImplementedError): ray::WorkerDict.actor_rollout_compute_log_prob() (pid=121293, ip=172.17.0.2, actor_id=1a6def26a5cb5589a18174cf01000000, repr=<verl.single_controller.ray.base.WorkerDict object at 0x7efb02a56e40>)
  File "/root/AdaptThink/verl/single_controller/ray/base.py", line 439, in func
    return getattr(self.worker_dict[key], name)(*args, **kwargs)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^
  File "/root/AdaptThink/verl/single_controller/base/decorator.py", line 409, in inner
    return func(*args, **kwargs)
  File "/root/AdaptThink/src/adapt_think_fsdp_workers.py", line 513, in compute_log_prob
    output = self.actor.compute_log_prob(data=data)  # (bs, response_length)
  File "/root/AdaptThink/verl/workers/actor/dp_actor.py", line 223, in compute_log_prob
    _, log_probs = self._forward_micro_batch(micro_batch, temperature=temperature)
                   ~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/root/AdaptThink/verl/workers/actor/dp_actor.py", line 69, in _forward_micro_batch
    if 'multi_modal_inputs' in micro_batch:
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/root/miniconda3/envs/adapt_think/lib/python3.13/site-packages/tensordict/tensordict.py", line 2932, in __contains__
    raise NotImplementedError(
    ...<3 lines>...
    )
NotImplementedError: TensorDict does not support membership checks with the `in` keyword. If you want to check if a particular key is in your TensorDict, please use `key in tensordict.keys()` instead.
(adapt_think) root@C.26418106:~/AdaptThink$

---

### 🤖 Cursor Assistant

Good news - the flash attention error is resolved! Now you have a different error with TensorDict. This is a breaking change in newer versions of tensordict.

The error says: **"TensorDict does not support membership checks with the `in` keyword"**. You need to use `key in tensordict.keys()` instead.

Let me find and fix all occurrences:

---

### 🤖 Cursor Assistant

Now let me fix the TensorDict membership check issues in both files:

---

### 🤖 Cursor Assistant

Now let me check if there are other TensorDict membership checks in the rollout workers:

---

### 🤖 Cursor Assistant

Perfect! I've fixed the TensorDict membership check issues in two files:

## Fixed Files:
1. ✅ `/verl/workers/actor/dp_actor.py` (line 69)
2. ✅ `/verl/workers/critic/dp_critic.py` (line 53)

Both now use `if 'multi_modal_inputs' in micro_batch.keys():` instead of `if 'multi_modal_inputs' in micro_batch:`

## Summary of All Fixes:

**Issue 1: Flash Attention ABI Error** ✅
- Root cause: C++ ABI incompatibility between flash-attn and PyTorch 2.6.0
- Solution: You can either:
  - Disable flash attention: `export TRANSFORMERS_NO_FLASH_ATTN=1`
  - Or install the correct wheel (but it seems the pre-built wheels still have issues)

**Issue 2: TensorDict Membership Check** ✅
- Root cause: Breaking change in newer tensordict versions that don't support `in` keyword
- Solution: Changed to use `.keys()` method

## Next Steps:

Try running your code again:

```bash
# Set environment variable to disable flash attention
export TRANSFORMERS_NO_FLASH_ATTN=1

# Run your training
python -m src.main_ppo [your args]
```

If you encounter any more TensorDict-related errors, let me know and I'll fix those too. The pattern is always the same: change `'key' in tensordict` to `'key' in tensordict.keys()`.

---


*Exported from [Cursor View](https://github.com/saharmor/cursor-view)*