fastcov
A massively parallel gcov wrapper for generating intermediate coverage formats fast
Decision gist · record as of 2026-08-14
Yes. Fastcov is actively maintained, has no dependencies, installs easily, and solves a real performance problem for C/C++ projects generating coverage reports. The MIT license is permissive. The only real constraint is the GCC 9.0.0 requirement—if your project meets that and uses gcov-based coverage, fastcov is a straightforward win for CI speed.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- GCC version 9.0.0 or later required; object files must be compiled with absolute include paths or from the same root directory; Python 3.8 minimum.
- Low friction: pure Python wheel with no runtime dependencies.
- Actively maintained as of 2026-07-15 with stable production status.
License · maintenance · safety
mit (permissive) — MIT license permits unrestricted use, modification, and distribution with minimal restrictions—suitable for both open-source and commercial projects.
last release 2026-05-29 (77 days) · last repo commit 2026-07-15 · 121 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 117,396 downloads/mo, #12,164 on PyPI
Alternatives
Verify before relying
pip install fastcov
fastcov.py --gcov gcov-9 --exclude /usr/include --lcov -o report.info
genhtml -o coverage_report report.info- Whether fastcov's parallelization speedup (claimed as 100x faster than lcov) holds across different project sizes and core counts.
- Compatibility with non-GCC compilers (e.g., Clang) for coverage generation.
- Whether the Docker image is the recommended deployment method or if native installation is equally supported.
What it is and what it does
Fastcov is a Python tool that wraps gcov to generate code coverage reports in multiple formats—JSON, LCOV info, and SonarQube XML. It parallelizes gcov execution across multiple cores to process large numbers of .gcda files much faster than traditional tools like lcov. The tool is designed as a drop-in replacement for lcov in C/C++ projects, handling the intermediate coverage format generation that can then be consumed by report generators like genhtml or uploaded to services like Codecov and Coveralls.
The package requires GCC 9.0.0 or later (for JSON intermediate format and stdout streaming support) and Python 3.8 minimum. Object files must be compiled with absolute include paths or from the same root directory. Fastcov supports filtering by file path using substring matching, branch coverage selection, combining multiple coverage reports, and exclusion marker scanning. It ships as a single-file Python script that can be copied directly or installed via pip, with optional utility scripts for summarizing coverage and converting to SonarQube format.
Use it for
- Accelerate CI/CD coverage report generation in large C/C++ projects with hundreds of .gcda files.
- Combine coverage reports from multiple test runs or build configurations into a single unified report.
- Generate coverage reports in SonarQube XML format for integration with SonarQube quality gates.
- Filter coverage data to exclude system headers and test files before publishing to coverage services.
- Check coverage thresholds (function, line, branch) in CI pipelines using the fastcov_summary utility.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
Fastcov is actively maintained, has no dependencies, installs easily, and solves a real performance problem for C/C++ projects generating coverage reports. The MIT license is permissive. The only real constraint is the GCC 9.0.0 requirement—if your project meets that and uses gcov-based coverage, fastcov is a straightforward win for CI speed.
Install
fastcov on PyPI
Before you install
Low friction: pure Python wheel with no runtime dependencies. Actively maintained as of 2026-07-15 with stable production status. Requires GCC 9.0.0 or later and Python 3.8 minimum.
GCC version 9.0.0 or later required; object files must be compiled with absolute include paths or from the same root directory; Python 3.8 minimum.
License in practice
MIT license permits unrestricted use, modification, and distribution with minimal restrictions—suitable for both open-source and commercial projects.
Quickstart
pip install fastcov
fastcov.py --gcov gcov-9 --exclude /usr/include --lcov -o report.info
genhtml -o coverage_report report.infoVerify before relying
- Whether fastcov's parallelization speedup (claimed as 100x faster than lcov) holds across different project sizes and core counts.
- Compatibility with non-GCC compilers (e.g., Clang) for coverage generation.
- Whether the Docker image is the recommended deployment method or if native installation is equally supported.
Package facts
| License | mit permissive |
| Python support | Supports the current Python release >=3.8 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | None |
| Maintenance | Actively maintained 77 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 117,396 / month, #12,164 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Development Status :: 5 - Production/StableEnvironment :: ConsoleIntended Audience :: DevelopersLicense :: OSI Approved :: MIT LicenseOperating System :: MacOSOperating System :: Microsoft :: WindowsOperating System :: POSIX :: LinuxOperating System :: UnixProgramming Language :: Python :: 3Programming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: 3.8Topic :: Utilities |
Evidence: fastcov-1.17-py2.py3-none-any.whl
Tags
Let your AI agent find packages like this
Example. Real query, live index.
You found this page by searching. An agent finds it by wishing: SkillFed indexes 14,416 PyPI packages by what they can do, searchable in plain language.
wish › “gcov coverage report generator”
- fastcovFastcov generates code coverage reports in JSON, LCOV, and SonarQube…
- gcovrGcovr processes GCC code coverage data and generates human-readable…
- coverage-badgeGenerates SVG coverage badges from Coverage.py data files, displaying…
Give your agent the search over MCP, or paste the wish link into any chat.
More Utilities packages
Converts domain names between Unicode and ASCII-compatible encoding (Punycode) according to IDNA 2008 and Unicode Technical Standard 46, with security validation and broader script coverage than the standard library.
Install it if you work with internationalized domain names, need to validate domains, or use HTTP clients that depend on it transitively.
Detects and normalizes text encoding from unknown or ambiguous sources, supporting all IANA character sets that Python's core library provides codecs for, with the ability to register custom codecs.
Setuptools is a Python build backend and package management tool that handles building, distributing, and installing Python packages, including support for C/C++ extension modules.
Pluggy provides a plugin system that lets you define hook specifications and register implementations to be called in sequence, enabling extensible Python applications without tight coupling.
Install it if you're building an extensible application or framework.
Pygments is a syntax highlighter that colorizes source code and text in over 500 languages and formats, outputting to HTML, LaTeX, RTF, SVG, images, or ANSI terminal sequences.
Install it if you need to display or transform source code.
Six provides utility functions to write Python code that runs on both Python 2.7 and Python 3.3+, smoothing over language differences between the two versions.
See also gcovr · lcov-cobertura · diff-cover · slipcover · junit-xml-2 · flake8-formatter-junit-xml · colcon-parallel-executor · bigquery-schema-generator · colcon-cmake · pyucis