Using Hatch in Python 3.6 is technically not allowed about soupsieve

[facelessuser]

Closing this as it seems hatch on py 3.6 is perfectly acceptable.

[darkshram]

All versions of hatchling require Python >= 3.7. There is no way to install soupsieve 2.3.2 with Python 3.6 without setup.py and setup.cfg.

[facelessuser]

I was able to install it on Python 3.6

[darkshram]

Yes, installation of hatchling with pip is possible (hatchling-0.21.1-py2.py3-none-any.whl), but trying to install hatchling 0.21.1 from source is not, which is a problem for distro packagers.

PKG-INFO from hatchling 0.21.1 does not include Python 3.6.

Metadata-Version: 2.1
Name: hatchling
Version: 0.21.1
Summary: Modern, extensible Python build backend
Project-URL: Funding, https://github.com/sponsors/ofek
Project-URL: History, https://ofek.dev/hatch/dev/history/
Project-URL: Homepage, https://ofek.dev/hatch/latest/
Project-URL: Source, https://github.com/ofek/hatch/tree/master/backend
Project-URL: Tracker, https://github.com/ofek/hatch/issues
Author-email: Ofek Lev <[email protected]>
Keywords: build,hatch,packaging
Classifier: Development Status :: 5 - Production/Stable
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License
Classifier: Natural Language :: English
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3.10
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Classifier: Topic :: Software Development :: Build Tools
Classifier: Topic :: Software Development :: Libraries :: Python Modules
Requires-Dist: editables>=0.2; python_version > '3'
Requires-Dist: importlib-metadata; python_version < '3.8'
Requires-Dist: packaging>=21.3; python_version > '3'
Requires-Dist: packaging~=20.9; python_version < '3'
Requires-Dist: pathspec>=0.9
Requires-Dist: pluggy>=1.0.0; python_version > '3'
Requires-Dist: pluggy~=0.13; python_version < '3'
Requires-Dist: tomli>=1.2.2; python_version > '3'
Requires-Dist: toml~=0.10.2; python_version < '3'
Description-Content-Type: text/markdown

# Hatchling

[facelessuser]

It doesn't list it in the classifiers, but that doesn't affect building or installing as it is just informational, but it doesn't restrict Python 3.6. There is no `python_requires=">=3.7". I'm not seeing the issue.

[darkshram]

Had to patch PKG-INFO and src/hatchling/ouroboros.py from hatchling 0.21.1 to make rpmbuild happy.

diff -Naur hatchling-0.21.1.orig/PKG-INFO hatchling-0.21.1/PKG-INFO
--- hatchling-0.21.1.orig/PKG-INFO	2020-02-01 18:00:00.000000000 -0600
+++ hatchling-0.21.1/PKG-INFO	2022-05-02 00:14:37.368183288 -0500
@@ -16,6 +16,7 @@
 Classifier: Operating System :: OS Independent
 Classifier: Programming Language :: Python :: 2.7
 Classifier: Programming Language :: Python :: 3.10
+Classifier: Programming Language :: Python :: 3.6
 Classifier: Programming Language :: Python :: 3.7
 Classifier: Programming Language :: Python :: 3.8
 Classifier: Programming Language :: Python :: 3.9
diff -Naur hatchling-0.21.1.orig/src/hatchling/ouroboros.py hatchling-0.21.1/src/hatchling/ouroboros.py
--- hatchling-0.21.1.orig/src/hatchling/ouroboros.py	2020-02-01 18:00:00.000000000 -0600
+++ hatchling-0.21.1/src/hatchling/ouroboros.py	2022-05-02 00:15:17.467223330 -0500
@@ -22,6 +22,7 @@
             'Natural Language :: English',
             'Operating System :: OS Independent',
             'Programming Language :: Python :: 2.7',
+            'Programming Language :: Python :: 3.6',
             'Programming Language :: Python :: 3.7',
             'Programming Language :: Python :: 3.8',
             'Programming Language :: Python :: 3.9',

Will detail procedure to build hatchling rpm package for rpm based Linux distributions using Python 3.6 (RHEL8, Almalinux8, etc.) and then build soupsieve 2.3.2 rpm package, beause surley somebody else using RHEL8/AlmaLinux8 will have the same issue to install hatchiling:

1. dnf -y install python3-devel pyproject-rpm-macros python3-editables python3-importlib-metadata python3-pathspec python3-pluggy python3-tomli
2. pip install hatchling==0.21.1 into build environment (mock) because circle dependency to itself (do not know how to bootstrap this package, yet)
3. mv /usr/local/lib/python3.6/site-packages/hatchling /usr/lib/python3.6/site-packages/
4. Build hatchling 0.21.1 rpm package with the patch to include Python 3.6 with the following lines added to spec file:

    BuildRequires:  pyproject-rpm-macros
    BuildRequires:  python3-editables >= 0.2 
    BuildRequires:  python3-importlib-metadata
    BuildRequires:  python3-pathspec >= 0.9
    BuildRequires:  python3-pluggy >= 0.13
    BuildRequires:  python3-tomli >= 1.2.2
    Requires:       python3-editables >= 0.2
    Requires:       python3-importlib-metadata
    Requires:       python3-pathspec >= 0.9
    Requires:       python3-pluggy >= 0.13
    Requires:       python3-tomli >= 1.2.2

5. Install patched python3-hatchling rpm package into the build environment (mock)
6. Build soupsieve 2.3.2 rpm package with BuildRequires for pyproject-rpm-macros and python3-hatchling >= 0.21.1 and using pyproject macros.

Spec file to build rpm package for RHEL8, AlmaLinux 8, etc., based on the spec file used for Fedora:

Name:           python-hatchling
Version:        2.3.2
Release:        1%{?dist}
Summary:        The build backend used by Hatch

License:        MIT
URL:            https://pypi.org/project/hatchling
Source0:        %{pypi_source hatchling}
# Man page in groff_man(7) format, hand-written for Fedora based on package
# metadata and --help output
Source1:        hatchling.1
Patch0:         python-hatchling-support-py36.patch

BuildArch:      noarch

BuildRequires:  python3-devel >= 3.6
BuildRequires:  pyproject-rpm-macros
BuildRequires:  python3-editables >= 0.2
BuildRequires:  python3-importlib-metadata
BuildRequires:  python3-pathspec >= 0.9
BuildRequires:  python3-pluggy >= 0.13
BuildRequires:  python3-tomli >= 1.2.2
# Has circle dependency with itself! Rebuild again with this line un-commented.
# BuildRequires:  python3-hatchling >= %{version}

%global common_description %{expand:
This is the extensible, standards compliant build backend used by Hatch.}

%description %{common_description}

%package -n python3-hatchling
Summary:        %{summary}
Requires:       python3 >= 3.6
Requires:       python3-editables >= 0.2
Requires:       python3-importlib-metadata
Requires:       python3-pathspec >= 0.9
Requires:       python3-pluggy >= 0.13
Requires:       python3-tomli >= 1.2.2

%description -n python3-hatchling %{common_description}

%prep
%autosetup -p1 -n hatchling-%{version}

# Cannot use -r (the default) with hatchling: “ValueError: build backend cannot
# provide build metadata (incl. runtime requirements) before build”. We work
# around this by writing the dependencies from src/hatchling/ourobororos.py
# into a text file.
PYTHONPATH="${PWD}/src" '%{python3}' <<EOF
from hatchling.ouroboros import CONFIG

deps = CONFIG['project']['dependencies']
with open('requirements.ouroboros.txt', 'w') as reqfile:
    reqfile.writelines(f'{dep}\n' for dep in deps)
EOF

%build
%pyproject_wheel

%install
%pyproject_install
install -t '%{buildroot}%{_mandir}/man1' -D -p -m 0644 '%{SOURCE1}'

%check
# It’s not yet clear how, or if, we can run the upstream tests.
# https://github.com/ofek/hatch/issues/120

%files -n python3-hatchling
%dir %{python3_sitelib}/hatchling-%{version}.dist-info/license_files
%license %{python3_sitelib}/hatchling-%{version}.dist-info/license_files/LICENSE.txt
%doc README.md
%{_bindir}/hatchling
%{_mandir}/man1/hatchling.1*
%{python3_sitelib}/hatchling
%{python3_sitelib}/hatchling-%{version}.dist-info

%changelog

So, yes, all these has solved the issue for me.

[facelessuser]

Okay, I didn't know that some packaging maintainers try to use the classifiers as authoritative info to control packaging.

Just as an FYI, soupsieve 2.3.2 will be the last version to be supported on Python 3.6. If I could back in time, I probably would have bumped sousieve to 2.4 and completely dropped Python 3.6 support as well, but I didn't realize the impact on packaging maintainers when I did it as a minor release. I'm sure I'm not the only one who doesn't fully understand how various packaging systems attempt to maintain Python code repos 🙃.

Anyways, I'm glad you were able to solve the issue. I'm sure your provided info is likely to be useful to others who may have to go down a similar path, so thanks for posting your resolution.