[libgpiod][PATCH] bindings: python: copy the license into distributions

[libgpiod][PATCH] bindings: python: copy the license into distributions

[Vincent Fazio]

Previously, the bindings called out the SPDX license identifier in the
pyproject.toml but did not include a copy of the license in either the
source or binary distributions.

This can be problematic for tools that rely on extracting license
information, such as Buildroot or other license auditing mechanisms.

Now, when distributions are built, the license is copied out of the
libgpiod source tarball and into the target distribution.

Closes: https://github.com/brgl/libgpiod/issues/162
Signed-off-by: Vincent Fazio <vfazio@gmail.com>
---
 bindings/python/setup.py | 52 +++++++++++++++++++++++++++++++++++++++-
 1 file changed, 51 insertions(+), 1 deletion(-)

diff --git a/bindings/python/setup.py b/bindings/python/setup.py
index 9555e54..7bf9246 100644
--- a/bindings/python/setup.py
+++ b/bindings/python/setup.py
@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: 2022 Bartosz Golaszewski <brgl@bgdev.pl>
 
 from os import getenv, path, unlink
-from shutil import copytree, rmtree
+from shutil import copy, copytree, rmtree
 
 from setuptools import Extension, setup
 from setuptools.command.build_ext import build_ext as orig_build_ext
@@ -17,6 +17,7 @@ SRC_BASE_URL = "https://mirrors.edge.kernel.org/pub/software/libs/libgpiod/"
 TAR_FILENAME = "libgpiod-{version}.tar.gz"
 ASC_FILENAME = "sha256sums.asc"
 SHA256_CHUNK_SIZE = 2048
+LICENSE_FILE = "LICENSE"
 
 
 def sha256(filename):
@@ -129,6 +130,53 @@ def fetch_tarball(command):
             copytree(path.join(base_dir, "include"), "./include")
             copytree(path.join(base_dir, "lib"), "./lib")
 
+            # Since the license file is not in the bindings directory, we cannot
+            # use the PEP-639 `license-files` property since the `Distribution`
+            # class is constructed during `setup`, parses pyproject.toml, and
+            # searches for the license file before we can copy files in to the
+            # directory*. If the file is not there, we get an error.
+            #
+            # To work around this, we manually copy the license file to the
+            # current directory and insert the license file into the metadata of
+            # the `Distribution` prior to the cmdclass building the distribution.
+            #
+            # Copying the file as `LICENSE` allows wheels built off of the sdist
+            # to automatically include the LICENSE, see:
+            # https://setuptools.pypa.io/en/latest/userguide/miscellaneous.html
+            #
+            # *Note: this is not technically true, but it would require doing
+            # something more complex like a custom build backend or to wrap
+            # `setup` or the `Distrubtion` object which get invoked/created
+            # multiple times and could fetch the tarball sources multiple times.
+            # Further, we only really care about the license file when building
+            # the released distribution files (sdist and wheels).
+
+            # Read the SPDX license identifier from pyproject.toml
+            license_file = None
+            with open("pyproject.toml", "rb") as f:
+                if sys.version_info >= (3, 11):
+                    import tomllib
+
+                    license_file = tomllib.load(f).get("project").get("license")
+                else:  # tomllib isn't standard, fall back to parsing by line
+                    for line in f.readlines():
+                        _line = line.decode()
+                        if _line.startswith("license = "):
+                            license_file = _line.split("=")[1].strip(' \r\n"')
+                            break
+
+            if license_file:  # Do not allow empty string or None
+                _path = path.join(base_dir, "LICENSES", f"{license_file}.txt")
+                if path.isfile(_path):
+                    # manually set the license list for the distribution after
+                    # the license file has been copied into the build directory.
+                    #
+                    # Note: that this must be in place prior to `egg_info.run`.
+                    # For further details, see `egg_info.find_sources` and
+                    # `manifest_maker.add_license_files`
+                    copy(_path, LICENSE_FILE)
+                    self.distribution.metadata.license_files = [LICENSE_FILE]
+
         # Save the libgpiod version for sdist
         open("libgpiod-version.txt", "w").write(LIBGPIOD_VERSION)
 
@@ -136,6 +184,8 @@ def fetch_tarball(command):
         command(self)
 
         # Clean up the build directory
+        if path.exists(LICENSE_FILE):
+            unlink(LICENSE_FILE)
         rmtree("./lib", ignore_errors=True)
         rmtree("./include", ignore_errors=True)
         unlink("libgpiod-version.txt")
-- 
2.43.0

Re: [libgpiod][PATCH] bindings: python: copy the license into distributions

[Bartosz Golaszewski]

On Sat, 28 Feb 2026 12:41:58 -0600, Vincent Fazio wrote:
> Previously, the bindings called out the SPDX license identifier in the
> pyproject.toml but did not include a copy of the license in either the
> source or binary distributions.
> 
> This can be problematic for tools that rely on extracting license
> information, such as Buildroot or other license auditing mechanisms.
> 
> [...]

Applied, thanks!

[1/1] bindings: python: copy the license into distributions
      https://git.kernel.org/brgl/c/21d1687b8882fc15dd78312049a97d6007b16c51

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>