librt-0.8 fails to build on cygwin

[henzef]

Compiling librt 0.7.8 works fine under cygwin, but 0.8 fails with the following error:

gcc -shared -Wl,--enable-auto-image-base build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx2/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx512/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/generic/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/neon32/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/neon64/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/sse41/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/sse42/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/ssse3/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/codec_choose.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/lib.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/librt_base64.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/tables/tables.o -L/usr/lib/python3.12/config -L/usr/lib -lpython3.12 -o build/lib.cygwin-3.6.6-x86_64-cpython-312/librt/base64.cpython-312-x86_64-cygwin.dll
/usr/lib/gcc/x86_64-pc-cygwin/13/../../../../x86_64-pc-cygwin/bin/ld: build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/librt_base64.o: in function `b64encode_internal':
/tmp/pip-install-6q709pts/librt_01b414965eac4373a48b79384ade6f5f/base64/librt_base64.c:81:(.text+0x140): undefined reference to `__imp_base64_encode'
/usr/lib/gcc/x86_64-pc-cygwin/13/../../../../x86_64-pc-cygwin/bin/ld: /tmp/pip-install-6q709pts/librt_01b414965eac4373a48b79384ade6f5f/base64/librt_base64.c:81:(.text+0x3fc): undefined reference to `__imp_base64_encode'
/usr/lib/gcc/x86_64-pc-cygwin/13/../../../../x86_64-pc-cygwin/bin/ld: build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/librt_base64.o: in function `b64decode_internal':
/tmp/pip-install-6q709pts/librt_01b414965eac4373a48b79384ade6f5f/base64/librt_base64.c:184:(.text+0x701): undefined reference to `__imp_base64_decode'
collect2: error: ld returned 1 exit status

Relevant versions:

• Python 3.12.12
• gcc 13.4.0
• binutils 2.46

Note that /usr/lib/python3.12/config does not exist, but /usr/lib/python3.12/config-3.12-x86_64-cygwin does. Creating a symlink does not help though

full build log

/tmp/pip-build-env-efa6odi8/overlay/lib/python3.12/site-packages/setuptools/config/_apply_pyprojecttoml.py:82: SetuptoolsDeprecationWarning: `project.license` as a TOML table is deprecated
!!
    ********************************************************************************
    Please use a simple string containing a SPDX expression for `project.license`. You can also use `project.license-files`. (Both options available on setuptools>=77.0.0).

    By 2027-Feb-18, you need to update your project and remove deprecated calls
    or your builds will no longer be supported.

    See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
    ********************************************************************************

!!

corresp(dist, value, root_dir)

/tmp/pip-build-env-efa6odi8/overlay/lib/python3.12/site-packages/setuptools/config/_apply_pyprojecttoml.py:61: SetuptoolsDeprecationWarning: License classifiers are deprecated.

!!
    ********************************************************************************
    Please consider removing the following classifiers in favor of a SPDX license expression:

    License :: OSI Approved :: MIT License

    See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
    ********************************************************************************

!!

dist._finalize_license_expression()

/tmp/pip-build-env-efa6odi8/overlay/lib/python3.12/site-packages/setuptools/dist.py:765: SetuptoolsDeprecationWarning: License classifiers are deprecated.

!!
    ********************************************************************************
    Please consider removing the following classifiers in favor of a SPDX license expression:

    License :: OSI Approved :: MIT License

    See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
    ********************************************************************************

!!

self._finalize_license_expression()

running egg_info

writing librt.egg-info/PKG-INFO

writing dependency_links to librt.egg-info/dependency_links.txt

writing top-level names to librt.egg-info/top_level.txt

reading manifest file 'librt.egg-info/SOURCES.txt'

reading manifest template 'MANIFEST.in'

adding license file 'LICENSE'

writing manifest file 'librt.egg-info/SOURCES.txt'

Getting requirements to build wheel ... done

Running command Preparing metadata (pyproject.toml)

/tmp/pip-build-env-efa6odi8/overlay/lib/python3.12/site-packages/setuptools/config/_apply_pyprojecttoml.py:82: SetuptoolsDeprecationWarning: project.license as a TOML table is deprecated

!!
    ********************************************************************************
    Please use a simple string containing a SPDX expression for `project.license`. You can also use `project.license-files`. (Both options available on setuptools>=77.0.0).

    By 2027-Feb-18, you need to update your project and remove deprecated calls
    or your builds will no longer be supported.

    See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
    ********************************************************************************

!!

corresp(dist, value, root_dir)

/tmp/pip-build-env-efa6odi8/overlay/lib/python3.12/site-packages/setuptools/config/_apply_pyprojecttoml.py:61: SetuptoolsDeprecationWarning: License classifiers are deprecated.

!!
    ********************************************************************************
    Please consider removing the following classifiers in favor of a SPDX license expression:

    License :: OSI Approved :: MIT License

    See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
    ********************************************************************************

!!

dist._finalize_license_expression()

/tmp/pip-build-env-efa6odi8/overlay/lib/python3.12/site-packages/setuptools/dist.py:765: SetuptoolsDeprecationWarning: License classifiers are deprecated.

!!
    ********************************************************************************
    Please consider removing the following classifiers in favor of a SPDX license expression:

    License :: OSI Approved :: MIT License

    See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
    ********************************************************************************

!!

self._finalize_license_expression()

running dist_info

creating /tmp/pip-modern-metadata-b9j5ucm6/librt.egg-info

writing /tmp/pip-modern-metadata-b9j5ucm6/librt.egg-info/PKG-INFO

writing dependency_links to /tmp/pip-modern-metadata-b9j5ucm6/librt.egg-info/dependency_links.txt

writing top-level names to /tmp/pip-modern-metadata-b9j5ucm6/librt.egg-info/top_level.txt

writing manifest file '/tmp/pip-modern-metadata-b9j5ucm6/librt.egg-info/SOURCES.txt'

reading manifest file '/tmp/pip-modern-metadata-b9j5ucm6/librt.egg-info/SOURCES.txt'

reading manifest template 'MANIFEST.in'

adding license file 'LICENSE'

writing manifest file '/tmp/pip-modern-metadata-b9j5ucm6/librt.egg-info/SOURCES.txt'

creating '/tmp/pip-modern-metadata-b9j5ucm6/librt-0.8.0.dist-info'

Preparing metadata (pyproject.toml) ... done

ilding wheels for collected packages: librt

Running command Building wheel for librt (pyproject.toml)

/tmp/pip-build-env-efa6odi8/overlay/lib/python3.12/site-packages/setuptools/config/_apply_pyprojecttoml.py:82: SetuptoolsDeprecationWarning: project.license as a TOML table is deprecated

!!
    ********************************************************************************
    Please use a simple string containing a SPDX expression for `project.license`. You can also use `project.license-files`. (Both options available on setuptools>=77.0.0).

    By 2027-Feb-18, you need to update your project and remove deprecated calls
    or your builds will no longer be supported.

    See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
    ********************************************************************************

!!

corresp(dist, value, root_dir)

/tmp/pip-build-env-efa6odi8/overlay/lib/python3.12/site-packages/setuptools/config/_apply_pyprojecttoml.py:61: SetuptoolsDeprecationWarning: License classifiers are deprecated.

!!
    ********************************************************************************
    Please consider removing the following classifiers in favor of a SPDX license expression:

    License :: OSI Approved :: MIT License

    See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
    ********************************************************************************

!!

dist._finalize_license_expression()

/tmp/pip-build-env-efa6odi8/overlay/lib/python3.12/site-packages/setuptools/dist.py:765: SetuptoolsDeprecationWarning: License classifiers are deprecated.

!!
    ********************************************************************************
    Please consider removing the following classifiers in favor of a SPDX license expression:

    License :: OSI Approved :: MIT License

    See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
    ********************************************************************************

!!

self._finalize_license_expression()

running bdist_wheel

running build

running build_py

running egg_info

writing librt.egg-info/PKG-INFO

writing dependency_links to librt.egg-info/dependency_links.txt

writing top-level names to librt.egg-info/top_level.txt

reading manifest file 'librt.egg-info/SOURCES.txt'

reading manifest template 'MANIFEST.in'

adding license file 'LICENSE'

writing manifest file 'librt.egg-info/SOURCES.txt'

creating build/lib.cygwin-3.6.6-x86_64-cpython-312/librt

copying librt/init.pyi -> build/lib.cygwin-3.6.6-x86_64-cpython-312/librt

copying librt/base64.pyi -> build/lib.cygwin-3.6.6-x86_64-cpython-312/librt

copying librt/internal.pyi -> build/lib.cygwin-3.6.6-x86_64-cpython-312/librt

copying librt/py.typed -> build/lib.cygwin-3.6.6-x86_64-cpython-312/librt

copying librt/strings.pyi -> build/lib.cygwin-3.6.6-x86_64-cpython-312/librt

copying librt/time.pyi -> build/lib.cygwin-3.6.6-x86_64-cpython-312/librt

copying librt/vecs.pyi -> build/lib.cygwin-3.6.6-x86_64-cpython-312/librt

running build_ext

building 'librt.internal' extension

creating build/temp.cygwin-3.6.6-x86_64-cpython-312

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/internal

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Iinternal -I/usr/include/python3.12 -c exc_ops.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/exc_ops.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Iinternal -I/usr/include/python3.12 -c getargsfast.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/getargsfast.o -O3 -Wno-unused-function

getargsfast.c: In function ‘skipitem_fast’:

getargsfast.c:562:10: warning: unused variable ‘c’ [-Wunused-variable]

562 |     char c = *format++;

|          ^

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Iinternal -I/usr/include/python3.12 -c init.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/init.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Iinternal -I/usr/include/python3.12 -c int_ops.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/int_ops.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Iinternal -I/usr/include/python3.12 -c internal/librt_internal.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/internal/librt_internal.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Iinternal -I/usr/include/python3.12 -c pythonsupport.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/pythonsupport.o -O3 -Wno-unused-function

gcc -shared -Wl,--enable-auto-image-base build/temp.cygwin-3.6.6-x86_64-cpython-312/exc_ops.o build/temp.cygwin-3.6.6-x86_64-cpython-312/getargsfast.o build/temp.cygwin-3.6.6-x86_64-cpython-312/init.o build/temp.cygwin-3.6.6-x86_64-cpython-312/int_ops.o build/temp.cygwin-3.6.6-x86_64-cpython-312/internal/librt_internal.o build/temp.cygwin-3.6.6-x86_64-cpython-312/pythonsupport.o -L/usr/lib/python3.12/config -L/usr/lib -lpython3.12 -o build/lib.cygwin-3.6.6-x86_64-cpython-312/librt/internal.cpython-312-x86_64-cygwin.dll

building 'librt.strings' extension

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/strings

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Istrings -I/usr/include/python3.12 -c exc_ops.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/exc_ops.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Istrings -I/usr/include/python3.12 -c getargsfast.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/getargsfast.o -O3 -Wno-unused-function

getargsfast.c: In function ‘skipitem_fast’:

getargsfast.c:562:10: warning: unused variable ‘c’ [-Wunused-variable]

562 |     char c = *format++;

|          ^

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Istrings -I/usr/include/python3.12 -c init.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/init.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Istrings -I/usr/include/python3.12 -c int_ops.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/int_ops.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Istrings -I/usr/include/python3.12 -c pythonsupport.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/pythonsupport.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Istrings -I/usr/include/python3.12 -c strings/librt_strings.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/strings/librt_strings.o -O3 -Wno-unused-function

gcc -shared -Wl,--enable-auto-image-base build/temp.cygwin-3.6.6-x86_64-cpython-312/exc_ops.o build/temp.cygwin-3.6.6-x86_64-cpython-312/getargsfast.o build/temp.cygwin-3.6.6-x86_64-cpython-312/init.o build/temp.cygwin-3.6.6-x86_64-cpython-312/int_ops.o build/temp.cygwin-3.6.6-x86_64-cpython-312/pythonsupport.o build/temp.cygwin-3.6.6-x86_64-cpython-312/strings/librt_strings.o -L/usr/lib/python3.12/config -L/usr/lib -lpython3.12 -o build/lib.cygwin-3.6.6-x86_64-cpython-312/librt/strings.cpython-312-x86_64-cygwin.dll

building 'librt.base64' extension

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx2

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx512

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/generic

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/neon32

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/neon64

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/sse41

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/sse42

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/ssse3

creating build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/tables

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/arch/avx/codec.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx/codec.o -O3 -Wno-unused-function -mavx

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/arch/avx2/codec.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx2/codec.o -O3 -Wno-unused-function -mavx2

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/arch/avx512/codec.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx512/codec.o -O3 -Wno-unused-function -mavx

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/arch/generic/codec.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/generic/codec.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/arch/neon32/codec.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/neon32/codec.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/arch/neon64/codec.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/neon64/codec.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/arch/sse41/codec.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/sse41/codec.o -O3 -Wno-unused-function -msse4.1

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/arch/sse42/codec.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/sse42/codec.o -O3 -Wno-unused-function -msse4.2

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/arch/ssse3/codec.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/ssse3/codec.o -O3 -Wno-unused-function -mssse3

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/codec_choose.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/codec_choose.o -O3 -Wno-unused-function

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/lib.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/lib.o -O3 -Wno-unused-function

base64/lib.c:18:1: warning: ‘base64_stream_encode_init’ redeclared without dllimport attribute: previous dllimport ignored [-Wattributes]

18 | base64_stream_encode_init (struct base64_state *state, int flags)

| ^~~~~~~~~~~~~~~~~~~~~~~~~

base64/lib.c:31:1: warning: ‘base64_stream_encode’ redeclared without dllimport attribute: previous dllimport ignored [-Wattributes]

31 | base64_stream_encode

| ^~~~~~~~~~~~~~~~~~~~

base64/lib.c:43:1: warning: ‘base64_stream_encode_final’ redeclared without dllimport attribute: previous dllimport ignored [-Wattributes]

43 | base64_stream_encode_final

| ^~~~~~~~~~~~~~~~~~~~~~~~~~

base64/lib.c:68:1: warning: ‘base64_stream_decode_init’ redeclared without dllimport attribute: previous dllimport ignored [-Wattributes]

68 | base64_stream_decode_init (struct base64_state *state, int flags)

| ^~~~~~~~~~~~~~~~~~~~~~~~~

base64/lib.c:81:1: warning: ‘base64_stream_decode’ redeclared without dllimport attribute: previous dllimport ignored [-Wattributes]

81 | base64_stream_decode

| ^~~~~~~~~~~~~~~~~~~~

base64/lib.c:103:1: warning: ‘base64_encode’ redeclared without dllimport attribute: previous dllimport ignored [-Wattributes]

103 | base64_encode

| ^~~~~~~~~~~~~

base64/lib.c:136:1: warning: ‘base64_decode’ redeclared without dllimport attribute: previous dllimport ignored [-Wattributes]

136 | base64_decode

| ^~~~~~~~~~~~~

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/librt_base64.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/librt_base64.o -O3 -Wno-unused-function

base64/librt_base64.c: In function ‘b64encode_internal’:

base64/librt_base64.c:53:9: warning: unused variable ‘newline’ [-Wunused-variable]

53 |     int newline = 0; // TODO

|         ^~~~~~~

base64/librt_base64.c:52:20: warning: unused variable ‘writer’ [-Wunused-variable]

52 |     PyBytesWriter *writer;

|                    ^~~~~~

base64/librt_base64.c:51:25: warning: unused variable ‘out_len’ [-Wunused-variable]

51 |     Py_ssize_t bin_len, out_len;

|                         ^~~~~~~

base64/librt_base64.c:50:18: warning: unused variable ‘leftchar’ [-Wunused-variable]

50 |     unsigned int leftchar = 0;

|                  ^~~~~~~~

base64/librt_base64.c:49:19: warning: unused variable ‘this_ch’ [-Wunused-variable]

49 |     unsigned char this_ch;

|                   ^~~~~~~

base64/librt_base64.c:48:9: warning: unused variable ‘leftbits’ [-Wunused-variable]

48 |     int leftbits = 0;

|         ^~~~~~~~

base64/librt_base64.c:46:20: warning: unused variable ‘ascii_data’ [-Wunused-variable]

46 |     unsigned char *ascii_data;

|                    ^~~~~~~~~~

gcc -fno-strict-overflow -Wsign-compare -DNDEBUG -g -O3 -Wall -I. -Ibase64 -I/usr/include/python3.12 -c base64/tables/tables.c -o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/tables/tables.o -O3 -Wno-unused-function

gcc -shared -Wl,--enable-auto-image-base build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx2/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/avx512/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/generic/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/neon32/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/neon64/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/sse41/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/sse42/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/arch/ssse3/codec.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/codec_choose.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/lib.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/librt_base64.o build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/tables/tables.o -L/usr/lib/python3.12/config -L/usr/lib -lpython3.12 -o build/lib.cygwin-3.6.6-x86_64-cpython-312/librt/base64.cpython-312-x86_64-cygwin.dll

/usr/lib/gcc/x86_64-pc-cygwin/13/../../../../x86_64-pc-cygwin/bin/ld: build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/librt_base64.o: in function b64encode_internal': /tmp/pip-install-6q709pts/librt_01b414965eac4373a48b79384ade6f5f/base64/librt_base64.c:81:(.text+0x140): undefined reference to __imp_base64_encode'

/usr/lib/gcc/x86_64-pc-cygwin/13/../../../../x86_64-pc-cygwin/bin/ld: /tmp/pip-install-6q709pts/librt_01b414965eac4373a48b79384ade6f5f/base64/librt_base64.c:81:(.text+0x3fc): undefined reference to __imp_base64_encode' /usr/lib/gcc/x86_64-pc-cygwin/13/../../../../x86_64-pc-cygwin/bin/ld: build/temp.cygwin-3.6.6-x86_64-cpython-312/base64/librt_base64.o: in function b64decode_internal':

/tmp/pip-install-6q709pts/librt_01b414965eac4373a48b79384ade6f5f/base64/librt_base64.c:184:(.text+0x701): undefined reference to `__imp_base64_decode'

collect2: error: ld returned 1 exit status

error: command '/usr/bin/gcc' failed with exit code 1

[ilevkivskyi]

OK, I guess this is caused by

#define BASE64_SYMBOL_IMPORT __declspec(dllimport)
#define BASE64_SYMBOL_EXPORT __declspec(dllexport)

plus the fact the we don't have #define BASE64_EXPORTS anywhere (nor #define BASE64_STATIC_DEFINE). On all other compilers import/export define same visibility. I can try adding BASE64_EXPORTS but I have no way to test this.

cc @JukkaL who added this.

[ilevkivskyi]

@henzef I just released librt v0.8.1. Could you please check if it fixes your issue?

[maj0e]

I encountered the same problem, when one of our CI pipelines at work failed to install mypy in Cygwin, because building librt-0.8.0 from source failed.
With the new version v0.8.1 the build is fixed.
Thanks a lot.

[ilevkivskyi]

OK, thanks for confirming!

[henzef]

Yes, fixed for me as well. Thanks for the quick fix!