build-1.6.0 (Python module)

[Bruce Dubbs]

New minor version.

[Joe Locash]

####################
 1.6.0 (2026-08-27)
####################

**********
 Features
**********

- Add ``--report=PATH`` to write a machine-readable JSON report of built artifac
ts; ``--metadata`` now also accepts
  ``.whl`` files - by :user:`gaborbernat` (:issue:`198`)
- The ``srcdir`` argument now accepts ``.tar.gz`` source distributions, extracti
ng and building from them - by
  :user:`gaborbernat` (:issue:`311`)
- The "Unmet dependencies" error from ``--no-isolation`` builds now shows the wa
nted version, found version, and
  interpreter - by :user:`gaborbernat` (:issue:`504`)
- Add ``--sdist-extract-dir`` to extract the intermediate sdist into a persisten
t directory, enabling compiler cache reuse
  across rebuilds - by :user:`gaborbernat` (:issue:`614`)
- Add ``--env-dir`` to place the isolated build environment at a fixed path, ena
bling compiler cache reuse across builds -
  by :user:`gaborbernat` (:issue:`655`)
- Print a summary of resolved dependency versions (``name==version``) after inst
alling them in isolated builds - by
  :user:`gaborbernat` (:issue:`959`)
- On build failure, print a tip pointing to ``--env-dir`` and ``--sdist-extract-
dir`` for debugging and link to the "Debug
  a failed build" how-to - reported by :user:`dimpase`, implemented by :user:`ga
borbernat` (:issue:`966`)

**********
 Bugfixes
**********

- Drain verbose subprocess output inline instead of using a ``ThreadPoolExecutor
``, which silently swallowed logging
  errors - by :user:`henryiii` (:issue:`1098`)
- Reject a file passed as ``--env-dir`` with a clear error instead of a raw ``Fi
leExistsError`` - by :user:`henryiii` (:issue:`1100`)
- Emit CLI warnings to stderr instead of stdout, so they no longer corrupt ``--m
etadata`` JSON output on stdout - by
  :user:`ymyzk` (:issue:`1111`)
- Fix the Windows symlink support probe always returning ``False`` due to a stal
e object interpolated into the destination
  path - by :user:`henryiii` (:issue:`1118`)
- Fix ``metadata_path``'s build-backend fallback returning a nonexistent dist-in
fo path for wheels with a build tag - by
  :user:`henryiii` (:issue:`1119`)
- Write pip/uv requirements and constraints files with ``\n`` instead of ``os.li
nesep``, avoiding doubled ``\r\r\n`` line
  endings on Windows - by :user:`henryiii` (:issue:`1120`)
- Batch of small robustness fixes: correct macOS release parsing for the minimum
 pip version, avoid sharing the mutable
  default build-system table between builders, keep the original error when isolated-environment setup fails early, and
  raise ``BuildException`` for an invalid wheel - by :user:`henryiii` (:issue:`1121`)
- Decide color support independently for stdout and stderr instead of only checking ``stdout.isatty()``, so redirecting
  one stream no longer disables or leaks ANSI colors on the other - by :user:`henryiii` (:issue:`1123`)
- Pass ``--dependency-constraints-txt`` files through to the installer unmodified instead of re-parsing them into a
  deduplicated set of lines, fixing a case where a hashed requirement (e.g. from ``pip-compile --generate-hashes``) could
  have its ``--hash`` continuation line separated from its requirement line and silently dropped, depending on the
  interpreter's hash seed - by :user:`manfred-kaiser` (:issue:`1140`)

**********
 Removals
**********

- Remove ``exc_info`` parameter and attribute from ``BuildBackendException``. - by :user:`layday` (:issue:`1161`)

**************
 Deprecations
**************

- Deprecate :func:`build.util.project_wheel_metadata`; use ``python -m build --metadata`` instead - by :user:`gaborbernat` (:issue:`557`)
- Warn on config settings without a value (e.g. ``-C--my-flag``); use ``-C--my-flag=`` instead for compatibility with pip
  - by :user:`gaborbernat` (:issue:`640`)

Fixed at 95600e406b.