feat: reactive on 26.04

.github/workflows/tests.yml

@@ -3,7 +3,8 @@ name: Test Suite
 on:
   pull_request:
     branches: [ master ]
-
+  workflow_dispatch:
+
 jobs:
   unit:
     name: Unit tests
@@ -14,11 +15,12 @@ jobs:
           - '3.8'   # focal
           - '3.10'  # jammy
           - '3.12'  # noble
+          - '3.14'  # resolute
     steps:
     - name: Check out code
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
     - name: Setup Python
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install Tox
@@ -31,7 +33,7 @@ jobs:
     needs: unit
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Add fake tag for git describe
       run: git tag v0.0.0
     - uses: snapcore/action-build@v1
@@ -44,9 +46,13 @@ jobs:
   integration:
     strategy:
       matrix:
-        charmcraft_channel:
-          - "2.x/stable"
-          - "3.x/beta"
+        include:
+          - charmcraft_channel: "2.x/stable"
+            charmcraft_label: "2.x-stable"
+          - charmcraft_channel: "3.x/stable"
+            charmcraft_label: "3.x-stable"
+          - charmcraft_channel: "latest/candidate"
+            charmcraft_label: "latest-candidate"
     name: Integration test
     needs: build
     runs-on: ubuntu-latest
@@ -62,7 +68,7 @@ jobs:
         sudo iptables -F FORWARD
         sudo iptables -P FORWARD ACCEPT
     - name: Checkout layer-basic
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         repository: juju-solutions/layer-basic
 
@@ -109,8 +115,8 @@ jobs:
             architectures: [amd64]
         EOF
         charmcraft pack -p tests/charm-minimal -v
-    - name: Build reactive charm with charmcraft-3.x
-      if: ${{ matrix.charmcraft_channel == '3.x/beta' }}
+    - name: Build reactive charm with charmcraft-3.x on ubuntu@24.04
+      if: ${{ matrix.charmcraft_channel == '3.x/stable' }}
       run: |
         set -euxo pipefail
         sudo snap install --classic --channel ${{ matrix.charmcraft_channel }} charmcraft
@@ -141,6 +147,38 @@ jobs:
         EOF
         charmcraft pack -p tests/charm-minimal -v
         mv minimal_amd64.charm minimal_ubuntu-24.04-amd64.charm
+    - name: Build reactive charm with charmcraft latest/candidate on ubuntu@26.04
+      if: ${{ matrix.charmcraft_channel == 'latest/candidate' }}
+      run: |
+        set -euxo pipefail
+        sudo snap install --classic --channel ${{ matrix.charmcraft_channel }} charmcraft
+        cat << EOF | tee tests/charm-minimal/charmcraft.yaml
+        type: charm
+        parts:
+          charm-tools:
+            plugin: nil
+            override-build: |
+              ls -lR \$CRAFT_PROJECT_DIR/
+              snap install --dangerous --classic /root/project/charm-snap/charm_0.0.0_amd64.snap
+              rm -rf \$CRAFT_PROJECT_DIR/parts/charm/src/charm-snap
+          charm:
+            after: [charm-tools]
+            source: .
+            plugin: reactive
+            reactive-charm-build-arguments:
+              - -v
+              - --binary-wheels-from-source
+              - --upgrade-buildvenv-core-deps
+              - --ignore-requires-python
+            build-packages:
+              - python3-dev
+              - libpq-dev
+        base: ubuntu@26.04
+        platforms:
+          amd64:
+        EOF
+        charmcraft pack -p tests/charm-minimal -v
+        mv minimal_amd64.charm minimal_ubuntu-26.04-amd64.charm
     ## action to interactively debug CI failures.
     # - name: Setup upterm session
     #   if: failure()
@@ -149,15 +187,16 @@ jobs:
       if: always()
       uses: actions/upload-artifact@v4
       with:
-        name: charmcraft execution logs ${{ matrix.runs-on }}
+        name: charmcraft execution logs ${{ matrix.charmcraft_label }}
         path: ~/snap/charmcraft/common/cache/charmcraft/log/*.log
     - name: Upload built charms
       uses: actions/upload-artifact@v4
       with:
-        name: Built charms
+        name: Built charms ${{ matrix.charmcraft_label }}
         overwrite: true
         path: |
           minimal_ubuntu-18.04-amd64.charm
           minimal_ubuntu-20.04-amd64.charm
           minimal_ubuntu-22.04-amd64.charm
           minimal_ubuntu-24.04-amd64.charm
+          minimal_ubuntu-26.04-amd64.charm

charmtools/build/builder.py

@@ -163,6 +163,14 @@ class Builder(object):
     DEFAULT_SERIES = 'trusty'
     METRICS_URL = 'https://www.google-analytics.com/collect'
     METRICS_ID = 'UA-96529618-2'
+    CHARMCRAFT_BUILD_PACKAGES = (
+        'git',
+        'virtualenv',
+        'python3-venv',
+        'python3-pip',
+        'python3-setuptools',
+        'python3-wheel',
+    )
 
     def __init__(self):
         self.config = BuildConfig()
@@ -778,13 +786,19 @@ def workaround_charmcraft_maybe_ensure_build_packages(self):
         The charmcraft reactive plugin ought to provide the bare minimum
         of build package dependencies, however until it does let's help
         here under the right circumstances.
+
+        Keep this list conservative and limited to generic tooling needed by
+        ``charm build`` itself. Charm-specific native dependencies still belong
+        in the charm's ``build-packages``.
         """
         if (os.geteuid() == 0
                 and (os.environ.get('CRAFT_PART_NAME', None)
                      or os.environ.get('CHARMCRAFT_PART_NAME', None))):
+            packages = self.CHARMCRAFT_BUILD_PACKAGES
             log.warning('Probably running as root in charmcraft, proactively '
-                        'installing the `git` and `virtualenv` packages.')
-            subprocess.run(('apt', '-y', 'install', 'git', 'virtualenv'),
+                        'installing the minimum charm build packages: %s.',
+                        ', '.join(packages))
+            subprocess.run(('apt', '-y', 'install') + packages,
                            check=True, env=utils.host_env())
 
     def generate(self):

charmtools/build/tactics.py

@@ -4,6 +4,7 @@
 import logging
 import os
 import re
+import sys
 import tarfile
 import tempfile
 import zipfile
@@ -1064,6 +1065,13 @@ class WheelhouseTactic(ExactMatch, Tactic):
     _default_cons = [
         "setuptools<82",
     ]
+    _python314_requirement_overrides = [
+        (
+            'Cython',
+            "Cython>=3.1,<4;python_version >= '3.14'",
+            'Cython 0.29.x does not build on Python 3.14',
+        ),
+    ]
 
     def __init__(self, *args, **kwargs):
         super(WheelhouseTactic, self).__init__(*args, **kwargs)
@@ -1217,15 +1225,17 @@ def _add(self, wheelhouse, *reqs, constraints=None):
             _ignore_requires_python = ('--ignore-requires-python', )
             env = self._get_env()
             try:
-                if self.binary_build_from_source or self.binary_build:
-                    # Handle constraints
-                    if constraints:
-                        env['PIP_CONSTRAINT'] = constraints
-                        env['PIP_BUILD_CONSTRAINT'] = constraints
-                    else:
-                        env.pop('PIP_CONSTRAINT', None)
-                        env.pop('PIP_BUILD_CONSTRAINT', None)
+                # Apply constraints to both dependency resolution and PEP 517
+                # build environments. This is needed for source downloads too,
+                # because pip may need to build sdists to inspect metadata.
+                if constraints:
+                    env['PIP_CONSTRAINT'] = str(constraints)
+                    env['PIP_BUILD_CONSTRAINT'] = str(constraints)
+                else:
+                    env.pop('PIP_CONSTRAINT', None)
+                    env.pop('PIP_BUILD_CONSTRAINT', None)
 
+                if self.binary_build_from_source or self.binary_build:
                     self._pip('wheel',
                               *_no_binary_opts
                               if self.binary_build_from_source else tuple(),
@@ -1389,8 +1399,50 @@ def _process_per_layer(self, wheelhouse):
         log.debug('Per-layer wheelhouse is not compatible with constraints')
         self._add(wheelhouse, '-r', self.entity)
 
+    def _apply_python_requirement_overrides(self, python_version=None):
+        """Apply requirement overrides needed by the target build Python version."""
+        python_version = python_version or sys.version_info
+        if python_version < (3, 14):
+            return
+
+        override_names = {
+            safe_name(name)
+            for name, _line, _reason in self._python314_requirement_overrides
+        }
+        updated_lines = []
+        overridden = set()
+        for line in self.lines or []:
+            try:
+                req = next(requirements.parse(line))
+                req_name = safe_name(req.name)
+            except (StopIteration, ValueError):
+                updated_lines.append(line)
+                continue
+
+            if req_name in override_names:
+                updated_lines.append(
+                    f'# {line}  # overridden by charm-tools for Python 3.14'
+                )
+                overridden.add(req_name)
+            else:
+                updated_lines.append(line)
+
+        if overridden:
+            updated_lines.append('# Default Python 3.14 wheelhouse overrides')
+            for name, line, reason in self._python314_requirement_overrides:
+                if safe_name(name) in overridden:
+                    updated_lines.append(f'# {reason}')
+                    updated_lines.append(line)
+            updated_lines.append('')
+            self.lines = updated_lines
+
     def _process_combined(self, wheelhouse):
         self.read()
+        if self._venv:
+            python_version = utils.get_python_version(self._venv, env=self._get_env())
+        else:
+            python_version = sys.version_info
+        self._apply_python_requirement_overrides(python_version)
         log.debug('Processing wheelhouse:')
         for line in self.lines or []:
             log.debug('  %s', line.strip())

charmtools/diff_match_patch.py

@@ -1815,7 +1815,7 @@ def patch_fromText(self, textline):
       return patches
     text = textline.split('\n')
     while len(text) != 0:
-      m = re.match("^@@ -(\d+),?(\d*) \+(\d+),?(\d*) @@$", text[0])
+      m = re.match(r"^@@ -(\d+),?(\d*) \+(\d+),?(\d*) @@$", text[0])
       if not m:
         raise ValueError("Invalid patch string: " + text[0])
       patch = patch_obj()

docs/changelog.rst

@@ -4,6 +4,12 @@ Changelog
 Current release
 ^^^^^^^^^^^^
 
+* Add Python 3.14 / Ubuntu 26.04 CI coverage for reactive charm builds
+* Add `legacy-cgi` dependency for Python 3.13+ template support
+* Move the snap build to `core24` so modern source builds can use the packaged `pathspec`
+* Fix snap build with modern `virtualenv` while keeping source builds on all architectures
+* Relax the `virtualenv` dependency for newer Python compatibility
+* Install additional generic build tooling in the charmcraft workaround
 * Add ability to specify constraints for `WheelhouseTactic` (#693)
 * Fix `charm-tools` version (#692)
 * Pin `setuptools` < 82 and drop archived `vergit` dependency (#689)

setup.py

@@ -61,18 +61,21 @@
         exclude=["*.tests", "*.tests.*", "tests.*", "tests"]),
     install_requires=[
         'cheetah3>=3.0.0,<4.0',
+        'legacy-cgi;python_version >= "3.13"',
         'pyyaml>=5.0,!=5.4.0,!=5.4.1,!=6.0,<7.0',
         'requests>=2.0.0,<3.0.0',
+        'six>=1.10',
         'blessings<2.0',
         'ruamel.yaml<0.16.0;python_version < "3.7"',
         'pathspec<=0.3.4;python_version < "3.7"',
         'ruamel.yaml<0.18;python_version >= "3.7"',
-        'pathspec<0.11;python_version >= "3.7"',
+        'pathspec>=0.10.1,<0.13;python_version >= "3.7"',
         'otherstuf<=1.1.0',
         'path<17',
         'pip>=1.5.4',
         'jujubundlelib<0.6',
-        'virtualenv>=1.11.4,<21',
+        'virtualenv>=20.25;python_version < "3.14"',
+        'virtualenv>=20.26;python_version >= "3.14"',
         'colander<1.9',
         'jsonschema<4.18.0',
         'keyring<24',