I'm having trouble with the latest Poky builds (core-image-minimal) and believe I narrowed down the issue to this commit.

I see python3-flit-core is referenced in recipetool and believe I saw something related to this (though my scrollback wasn't enough).

See the three tests below (separated via "--").

Test 1 - commit previous to flit-core - success:

Build Configuration:
BB_VERSION = "2.12.0"
BUILD_SYS = "x86_64-linux"
NATIVELSBSTRING = "universal"
TARGET_SYS = "arm-poky-linux-gnueabi"
MACHINE = "beaglebone-yocto"
DISTRO = "poky"
DISTRO_VERSION = "5.2"
TUNE_FEATURES = "arm vfp cortexa8 neon callconvention-hard"
TARGET_FPU = "hard"
meta = "HEAD:557c12455e406571e829872fa83878510cbe94a1"
meta-selinux = "master:32adf788c70a3e75e947ea7394b9a746686bb01e"
meta-python
meta-oe = "HEAD:f3f094acd6c83c757378bae20d398cb14783e731"
meta-poky
meta-yocto-bsp = "HEAD:557c12455e406571e829872fa83878510cbe94a1"
meta-clang = "master:02e254ba1fb4937530d94a154b4c713c904c2d06"
meta-security = "master:784ca4b6584101e971b2d5d76ec7b716ad1301b5"

Test 2 - failure - HEAD:

Build Configuration:
BB_VERSION = "2.12.0"
BUILD_SYS = "x86_64-linux"
NATIVELSBSTRING = "universal"
TARGET_SYS = "arm-poky-linux-gnueabi"
MACHINE = "beaglebone-yocto"
DISTRO = "poky"
DISTRO_VERSION = "5.2"
TUNE_FEATURES = "arm vfp cortexa8 neon callconvention-hard"
TARGET_FPU = "hard"
meta = "master:e3d24e5cd8eee5d0d232abdfef33cacf0ad96787"
meta-selinux = "master:32adf788c70a3e75e947ea7394b9a746686bb01e"
meta-python
meta-oe = "master:1d6095b73fa21062fde2b347cd61b6c5104390d9"
meta-poky
meta-yocto-bsp = "master:e3d24e5cd8eee5d0d232abdfef33cacf0ad96787"
meta-clang = "master:02e254ba1fb4937530d94a154b4c713c904c2d06"
meta-security = "master:784ca4b6584101e971b2d5d76ec7b716ad1301b5"

ERROR: python3-markupsafe-native-3.0.2-r0 do_compile: Execution of '[...]/poky/build/tmp/work/x86_64-linux/python3-markupsafe-native/3.0.2/temp/run.do_compile.2646889' failed with exit code 1
ERROR: Logfile of failure stored in: [...]/poky/build/tmp/work/x86_64-linux/python3-markupsafe-native/3.0.2/temp/log.do_compile.2646889
Log data follows:
| DEBUG: Executing shell function do_compile

| * Getting build dependencies for wheel...
| [...]/poky/build/tmp/work/x86_64-linux/python3-markupsafe-native/3.0.2/recipe-sysroot-native/usr/lib/python3.13/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 2026-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)

| [...]/poky/build/tmp/work/x86_64-linux/python3-markupsafe-native/3.0.2/recipe-sysroot-native/usr/lib/python3.13/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 :: BSD License
|
| See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.

| ********************************************************************************
|

| !! dist._finalize_license_expression()
| [...]/poky/build/tmp/work/x86_64-linux/python3-markupsafe-native/3.0.2/recipe-sysroot-native/usr/lib/python3.13/site-packages/setuptools/dist.py:759: SetuptoolsDeprecationWarning: License classifiers are deprecated.

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

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

| self._finalize_license_expression()
| usage: _in_process.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]

| ERROR Backend subprocess exited when trying to invoke get_requires_for_build_wheel
| WARNING: exit code 1 from a shell command.
ERROR: Task (virtual:native:[...]/poky/meta/recipes-devtools/python/python3-markupsafe_3.0.2.bb:do_compile) failed with exit code '1'

Test 3 - this flit commit - failure:

Build Configuration:

BB_VERSION = "2.12.0"

BUILD_SYS = "x86_64-linux"
NATIVELSBSTRING = "universal"

TARGET_SYS = "arm-poky-linux-gnueabi"
MACHINE = "beaglebone-yocto"
DISTRO = "poky"
DISTRO_VERSION = "5.2"
TUNE_FEATURES = "arm vfp cortexa8 neon callconvention-hard"
TARGET_FPU = "hard"
meta = "HEAD:0034c8aac358fe613018f0456ad7c68c2da04684"
meta-selinux = "master:32adf788c70a3e75e947ea7394b9a746686bb01e"
meta-python
meta-oe = "HEAD:f3f094acd6c83c757378bae20d398cb14783e731"
meta-poky
meta-yocto-bsp = "HEAD:0034c8aac358fe613018f0456ad7c68c2da04684"
meta-clang = "master:02e254ba1fb4937530d94a154b4c713c904c2d06"
meta-security = "master:784ca4b6584101e971b2d5d76ec7b716ad1301b5"
[...]
NOTE: Executing Tasks
ERROR: python3-wheel-native-0.45.1-r0 do_compile: Execution of '[...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/temp/run.do_compile.2528661' failed with exit code 1
ERROR: Logfile of failure stored in: [...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/temp/log.do_compile.2528661
Log data follows:
| DEBUG: Executing shell function do_compile
| * Getting build dependencies for wheel...
|
| Traceback (most recent call last):
| File "[...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/recipe-sysroot-native/usr/lib/python3.13/site-packages/build/__main__.py", line 178, in _handle_build_error
| yield
| File "[...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/recipe-sysroot-native/usr/lib/python3.13/site-packages/build/__main__.py", line 429, in main
| built = build_call(
| args.srcdir,
| ...<5 lines>...
| args.installer,
| )
| File "[...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/recipe-sysroot-native/usr/lib/python3.13/site-packages/build/__main__.py", line 238, in build_package
| out = _build(isolation, srcdir, outdir, distribution, config_settings, skip_dependency_check, installer)
| File "[...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/recipe-sysroot-native/usr/lib/python3.13/site-packages/build/__main__.py", line 172, in _build
| return _build_in_current_env(srcdir, outdir, distribution, config_settings, skip_dependency_check)
| File "[...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/recipe-sysroot-native/usr/lib/python3.13/site-packages/build/__main__.py", line 151, in _build_in_current_env
| missing = builder.check_dependencies(distribution, config_settings or {})
| File "[...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/recipe-sysroot-native/usr/lib/python3.13/site-packages/build/_builder.py", line 243, in check_dependencies
| return {u for d in dependencies for u in check_dependency(d)}
| ~~~~~~~~~~~~~~~~^^^
| File "[...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/recipe-sysroot-native/usr/lib/python3.13/site-packages/build/_util.py", line 53, in check_dependency
| if req.specifier and not req.specifier.contains(dist.version, prereleases=True):
| ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| File "[...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/recipe-sysroot-native/usr/lib/python3.13/site-packages/packaging/specifiers.py", line 917, in contains
| item = Version(item)
| File "[...]/poky/build/tmp/work/x86_64-linux/python3-wheel-native/0.45.1/recipe-sysroot-native/usr/lib/python3.13/site-packages/packaging/version.py", line 200, in __init__
| match = self._regex.search(version)
| TypeError: expected string or bytes-like object, got 'NoneType'
|
| ERROR expected string or bytes-like object, got 'NoneType'
| WARNING: exit code 1 from a shell command.