Missing coverage reports for platform-specific code

[trxvorr]

Codecov reports "Missing Coverage" for platform-specific code (e.g., # pragma: win32 only) when running on CI environments where that code is not executed (e.g. Linux). This creates noise and lowers the coverage score unfairly.

For example, src/borg/platform/__init__.py has imports guarded by # pragma: win32 only, which are flagged as missed on Linux CI runs.

Root Cause

The pyproject.toml configuration for coverage reports ([tool.coverage.report]) currently lists exclude_lines but is missing several platform-specific pragmas used in the codebase.

It currently includes:

• "pragma: no cover"
• "pragma: freebsd only"
• "pragma: unknown platform only"

It is missing:

• "pragma: win32 only"
• "pragma: posix only"
• "pragma: linux only"
• "pragma: darwin only"
• "pragma: netbsd only"

Proposed Solution

Update pyproject.toml to include these missing pragmas in exclude_lines. This ensures that platform-specific blocks are correctly excluded from coverage calculations on platforms where they are not expected to run.