This release bundles bugfixes and improvements from about 9 months of work.

• install/upgrade: pip install -U gcovr
• full changelog and documentation: https://gcovr.com/en/5.1/changelog.html

Highlights include consistent support for symlinks including on Windows, and richer reports with function coverage and decision coverage.

Breaking changes:

• Dropped support for Python 3.6 (#550)
• Changed xml configuration key to cobertura (#552)
• JSON summary output: all percentages are now reported from 0 to 100 (#570)

New features and notable changes:

• Report function coverage (#362, #515, #554)
• Consistent support for symlinks across operating systems
  • Support for Windows junctions (#535)
  • Symlinks are only resolved for evaluating filters (#565)
• Show error message on STDERR when --fail-under-line or --fail-under-branch fails (#502)
• Can report decision coverage with --decisions option (reasonably formatted C/C++ source files only, HTML and JSON output) (#350)
• Can create reproducible reports with the --timestamp option (#546)
• Improvements to exclusion markers (LINE/START/STOP)
  • Can ignore markers in code with --no-markers option (#361)
  • Can customize patterns with --exclude-pattern-prefix option (#561)
• Can use --cobertura as a less ambiguous alias for --xml. (#552)

Bug fixes and small improvements:

• Gcov is invoked without localization by setting LC_ALL=C (#513)
• Gcov is invoked without temporary directories (#525)
• Gcov: solved problems with file name limitations. (#528)
• Fixed "root" path in JSON summary report. (#548)
• Correctly resolve relative filters in configuration files. (#568)
• HTML output: indicate lines with excluded coverage (#503)
• HTML output: fixed sanity check to support empty files (#571)
• HTML output: support jinja2 >= 3.1 (#576)

Documentation:

• Split documentation into smaller pages (#552)
• Document used options for gcov (#528)

Internal changes:

• Replaced own logger with Python's logging module. (#540)
• New parser for .gcov file format, should be more robust. (#512)
• New tests
  • more compilers: clang-10 (#484), clang-13 (#527), gcc-9 (#527)
  • -fprofile-abs-path compiler option (#521)
  • enabled symlink tests for Windows (#539)
• Improvements to the test suite
  • Use Nox instead of Makefiles to manage QA checks (#516, #555)
  • Can run tests for all compiler versions in one go (#514)
  • More linter checks (#566) and code style enforcement with black (#579)
  • Better XML diffing with yaxmldiff (#495, #509)
  • Share test reference data between compiler versions where possible (#556)
  • Better environment variable handling (#493, #541)
  • Fixed glob patterns for collecting reference files (#533)
  • Add timeout for each single test. (#572)
• Improvements and fixes to the release process (#494, #537)
• Normalize shell scripts to Unix line endings (#538, #547)