evaluating-code-models

BigCode Evaluation Harness - Code Model Benchmarking

Quick Start

BigCode Evaluation Harness evaluates code generation models across 15+ benchmarks including HumanEval, MBPP, and MultiPL-E (18 languages).

Installation:

git clone https://github.com/bigcode-project/bigcode-evaluation-harness.git
cd bigcode-evaluation-harness
pip install -e .
accelerate config

Evaluate on HumanEval:

accelerate launch main.py \
  --model bigcode/starcoder2-7b \
  --tasks humaneval \
  --max_length_generation 512 \
  --temperature 0.2 \
  --n_samples 20 \
  --batch_size 10 \
  --allow_code_execution \
  --save_generations

View available tasks:

python -c "from bigcode_eval.tasks import ALL_TASKS; print(ALL_TASKS)"

Common Workflows

Workflow 1: Standard Code Benchmark Evaluation

Evaluate model on core code benchmarks (HumanEval, MBPP, HumanEval+).

Checklist:

Code Benchmark Evaluation:
- [ ] Step 1: Choose benchmark suite
- [ ] Step 2: Configure model and generation
- [ ] Step 3: Run evaluation with code execution
- [ ] Step 4: Analyze pass@k results

Step 1: Choose benchmark suite

Python code generation (most common):

• HumanEval: 164 handwritten problems, function completion
• HumanEval+: Same 164 problems with 80× more tests (stricter)
• MBPP: 500 crowd-sourced problems, entry-level difficulty
• MBPP+: 399 curated problems with 35× more tests

Multi-language (18 languages):

• MultiPL-E: HumanEval/MBPP translated to C++, Java, JavaScript, Go, Rust, etc.

Advanced:

• APPS: 10,000 problems (introductory/interview/competition)
• DS-1000: 1,000 data science problems across 7 libraries

Step 2: Configure model and generation

# Standard HuggingFace model
accelerate launch main.py \
  --model bigcode/starcoder2-7b \
  --tasks humaneval \
  --max_length_generation 512 \
  --temperature 0.2 \
  --do_sample True \
  --n_samples 200 \
  --batch_size 50 \
  --allow_code_execution

# Quantized model (4-bit)
accelerate launch main.py \
  --model codellama/CodeLlama-34b-hf \
  --tasks humaneval \
  --load_in_4bit \
  --max_length_generation 512 \
  --allow_code_execution

# Custom/private model
accelerate launch main.py \
  --model /path/to/my-code-model \
  --tasks humaneval \
  --trust_remote_code \
  --use_auth_token \
  --allow_code_execution

Step 3: Run evaluation

# Full evaluation with pass@k estimation (k=1,10,100)
accelerate launch main.py \
  --model bigcode/starcoder2-7b \
  --tasks humaneval \
  --temperature 0.8 \
  --n_samples 200 \
  --batch_size 50 \
  --allow_code_execution \
  --save_generations \
  --metric_output_path results/starcoder2-humaneval.json

Step 4: Analyze results

Results in results/starcoder2-humaneval.json:

{
  "humaneval": {
    "pass@1": 0.354,
    "pass@10": 0.521,
    "pass@100": 0.689
  },
  "config": {
    "model": "bigcode/starcoder2-7b",
    "temperature": 0.8,
    "n_samples": 200
  }
}

Workflow 2: Multi-Language Evaluation (MultiPL-E)

Evaluate code generation across 18 programming languages.

Checklist:

Multi-Language Evaluation:
- [ ] Step 1: Generate solutions (host machine)
- [ ] Step 2: Run evaluation in Docker (safe execution)
- [ ] Step 3: Compare across languages

Step 1: Generate solutions on host

# Generate without execution (safe)
accelerate launch main.py \
  --model bigcode/starcoder2-7b \
  --tasks multiple-py,multiple-js,multiple-java,multiple-cpp \
  --max_length_generation 650 \
  --temperature 0.8 \
  --n_samples 50 \
  --batch_size 50 \
  --generation_only \
  --save_generations \
  --save_generations_path generations_multi.json

Step 2: Evaluate in Docker container

# Pull the MultiPL-E Docker image
docker pull ghcr.io/bigcode-project/evaluation-harness-multiple

# Run evaluation inside container
docker run -v $(pwd)/generations_multi.json:/app/generations.json:ro \
  -it evaluation-harness-multiple python3 main.py \
  --model bigcode/starcoder2-7b \
  --tasks multiple-py,multiple-js,multiple-java,multiple-cpp \
  --load_generations_path /app/generations.json \
  --allow_code_execution \
  --n_samples 50

Supported languages: Python, JavaScript, Java, C++, Go, Rust, TypeScript, C#, PHP, Ruby, Swift, Kotlin, Scala, Perl, Julia, Lua, R, Racket

Workflow 3: Instruction-Tuned Model Evaluation

Evaluate chat/instruction models with proper formatting.

Checklist:

Instruction Model Evaluation:
- [ ] Step 1: Use instruction-tuned tasks
- [ ] Step 2: Configure instruction tokens
- [ ] Step 3: Run evaluation

Step 1: Choose instruction tasks

• instruct-humaneval: HumanEval with instruction prompts
• humanevalsynthesize-{lang}: HumanEvalPack synthesis tasks

Step 2: Configure instruction tokens

# For models with chat templates (e.g., CodeLlama-Instruct)
accelerate launch main.py \
  --model codellama/CodeLlama-7b-Instruct-hf \
  --tasks instruct-humaneval \
  --instruction_tokens "<s>[INST],</s>,[/INST]" \
  --max_length_generation 512 \
  --allow_code_execution

Step 3: HumanEvalPack for instruction models

# Test code synthesis across 6 languages
accelerate launch main.py \
  --model codellama/CodeLlama-7b-Instruct-hf \
  --tasks humanevalsynthesize-python,humanevalsynthesize-js \
  --prompt instruct \
  --max_length_generation 512 \
  --allow_code_execution

Workflow 4: Compare Multiple Models

Benchmark suite for model comparison.

Step 1: Create evaluation script

#!/bin/bash
# eval_models.sh

MODELS=(
  "bigcode/starcoder2-7b"
  "codellama/CodeLlama-7b-hf"
  "deepseek-ai/deepseek-coder-6.7b-base"
)
TASKS="humaneval,mbpp"

for model in "${MODELS[@]}"; do
  model_name=$(echo $model | tr '/' '-')
  echo "Evaluating $model"

  accelerate launch main.py \
    --model $model \
    --tasks $TASKS \
    --temperature 0.2 \
    --n_samples 20 \
    --batch_size 20 \
    --allow_code_execution \
    --metric_output_path results/${model_name}.json
done

Step 2: Generate comparison table

import json
import pandas as pd

models = ["bigcode-starcoder2-7b", "codellama-CodeLlama-7b-hf", "deepseek-ai-deepseek-coder-6.7b-base"]
results = []

for model in models:
    with open(f"results/{model}.json") as f:
        data = json.load(f)
        results.append({
            "Model": model,
            "HumanEval pass@1": f"{data['humaneval']['pass@1']:.3f}",
            "MBPP pass@1": f"{data['mbpp']['pass@1']:.3f}"
        })

df = pd.DataFrame(results)
print(df.to_markdown(index=False))

When to Use vs Alternatives

Use BigCode Evaluation Harness when:

• Evaluating code generation models specifically
• Need multi-language evaluation (18 languages via MultiPL-E)
• Testing functional correctness with unit tests (pass@k)
• Benchmarking for BigCode/HuggingFace leaderboards
• Evaluating fill-in-the-middle (FIM) capabilities

Use alternatives instead:

• lm-evaluation-harness: General LLM benchmarks (MMLU, GSM8K, HellaSwag)
• EvalPlus: Stricter HumanEval+/MBPP+ with more test cases
• SWE-bench: Real-world GitHub issue resolution
• LiveCodeBench: Contamination-free, continuously updated problems
• CodeXGLUE: Code understanding tasks (clone detection, defect prediction)

Supported Benchmarks

Benchmark	Problems	Languages	Metric	Use Case
HumanEval	164	Python	pass@k	Standard code completion
HumanEval+	164	Python	pass@k	Stricter evaluation (80× tests)
MBPP	500	Python	pass@k	Entry-level problems
MBPP+	399	Python	pass@k	Stricter evaluation (35× tests)
MultiPL-E	164×18	18 languages	pass@k	Multi-language evaluation
APPS	10,000	Python	pass@k	Competition-level
DS-1000	1,000	Python	pass@k	Data science (pandas, numpy, etc.)
HumanEvalPack	164×3×6	6 languages	pass@k	Synthesis/fix/explain
Mercury	1,889	Python	Efficiency	Computational efficiency

Common Issues

Issue: Different results than reported in papers

Check these factors:

# 1. Verify n_samples (need 200 for accurate pass@k)
--n_samples 200

# 2. Check temperature (0.2 for greedy-ish, 0.8 for sampling)
--temperature 0.8

# 3. Verify task name matches exactly
--tasks humaneval  # Not "human_eval" or "HumanEval"

# 4. Check max_length_generation
--max_length_generation 512  # Increase for longer problems

Issue: CUDA out of memory

# Use quantization
--load_in_8bit
# OR
--load_in_4bit

# Reduce batch size
--batch_size 1

# Set memory limit
--max_memory_per_gpu "20GiB"

Issue: Code execution hangs or times out

Use Docker for safe execution:

# Generate on host (no execution)
--generation_only --save_generations

# Evaluate in Docker
docker run ... --allow_code_execution --load_generations_path ...

Issue: Low scores on instruction models

Ensure proper instruction formatting:

# Use instruction-specific tasks
--tasks instruct-humaneval

# Set instruction tokens for your model
--instruction_tokens "<s>[INST],</s>,[/INST]"

Issue: MultiPL-E language failures

Use the dedicated Docker image:

docker pull ghcr.io/bigcode-project/evaluation-harness-multiple

Command Reference

Argument	Default	Description
--model	-	HuggingFace model ID or local path
--tasks	-	Comma-separated task names
--n_samples	1	Samples per problem (200 for pass@k)
--temperature	0.2	Sampling temperature
--max_length_generation	512	Max tokens (prompt + generation)
--batch_size	1	Batch size per GPU
--allow_code_execution	False	Enable code execution (required)
--generation_only	False	Generate without evaluation
--load_generations_path	-	Load pre-generated solutions
--save_generations	False	Save generated code
--metric_output_path	results.json	Output file for metrics
--load_in_8bit	False	8-bit quantization
--load_in_4bit	False	4-bit quantization
--trust_remote_code	False	Allow custom model code
--precision	fp32	Model precision (fp32/fp16/bf16)

Hardware Requirements

Model Size	VRAM (fp16)	VRAM (4-bit)	Time (HumanEval, n=200)
7B	14GB	6GB	~30 min (A100)
13B	26GB	10GB	~1 hour (A100)
34B	68GB	20GB	~2 hours (A100)

Resources

• GitHub: https://github.com/bigcode-project/bigcode-evaluation-harness
• Documentation: https://github.com/bigcode-project/bigcode-evaluation-harness/tree/main/docs
• BigCode Leaderboard: https://huggingface.co/spaces/bigcode/bigcode-models-leaderboard
• HumanEval Dataset: https://huggingface.co/datasets/openai/openai_humaneval
• MultiPL-E: https://github.com/nuprl/MultiPL-E

Agent operating procedure

1. Check the environment. Confirm the model, checkpoint, benchmark version and evaluation harness version.
2. Pin down the inputs. Confirm formats, identifiers and parameters from the data or the user. Ask rather than guess any value that changes the result.
3. Run a small version first. Evaluate on a small subset to verify prompts, parsing and scoring.
4. Execute the full task using the instructions and references above.
5. Validate the result. Use the benchmark's official splits and metrics; check for contamination; report variance across seeds or prompts.
6. Report. State what was run (versions, commands, parameters), what was checked, and what is still uncertain.

If this happens	Do this
Scores differ from published numbers	Check prompt format, few-shot settings and harness version before concluding.
A function, flag or endpoint in these instructions is missing in the installed version	Check the installed version's own documentation (help(), --help, official docs), adapt, and tell the user. Never invent an API.
A required input, identifier or parameter is ambiguous	Ask the user, or state the assumption explicitly before running.

Integrity rules

• Never fabricate results, parameters, identifiers, citations or statistics. If something cannot be run or verified, say so plainly.
• Report evaluation settings in full; never cherry-pick prompts, seeds or subsets.
• Treat version-specific details here as possibly outdated: confirm them against the official documentation for the installed version.
• Ask before actions that cost money, consume shared GPUs or cloud quota, touch personal or patient data, or cannot be undone.

Related skills

• evaluating-llms-harness: Evaluates LLMs across 60+ academic benchmarks (MMLU, HumanEval, GSM8K, TruthfulQA, HellaSwag).
• nemo-evaluator-sdk: Evaluates LLMs across 100+ benchmarks from 18+ harnesses (MMLU, HumanEval, GSM8K, safety, VLM) with multi-backend execution.