Raise minimum supported Python version to 3.11 (#842)

* Raise minimum supported Python version to 3.11

* Rebuild Conda configuration after restoring CI cache

---------

Co-authored-by: Christopher Rowley <github.com/cjdoris>

Author: cjdoris

.github/workflows/register-pypi.yml

@@ -17,7 +17,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v7
       with:
-        python-version: "3.10"
+        python-version: "3.11"
     - name: Install build
       run: >-
         python -m

.github/workflows/tests.yml

@@ -41,6 +41,17 @@ jobs:
 
       - uses: julia-actions/cache@v3
 
+      # The package cache includes Conda's build configuration, but not its root environment.
+      - name: Rebuild Conda configuration
+        shell: julia --color=yes {0}
+        env:
+          JULIA_PKG_PRECOMPILE_AUTO: '0'
+        run: |
+          using Pkg
+          Pkg.activate(; temp=true)
+          Pkg.add("Conda")
+          Pkg.build("Conda")
+
       - name: Build package
         uses: julia-actions/julia-buildpkg@v1
         env:
@@ -83,7 +94,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        pyversion: ['3', '3.10']
+        pyversion: ['3', '3.11']
         juliaexe: ["@JuliaPkg"]
         include:
         - os: ubuntu-latest

AGENTS.md

@@ -9,5 +9,10 @@
 
 The majority of tests live in the Julia package; Python tests cover functionality that cannot be exercised from Julia (e.g., JuliaCall-specific behavior). Run both suites—typically Julia first—in whichever order makes sense.
 
+- In restricted sandboxes, both suites need approval to write to the shared caches (`~/.julia` and `~/.cache/uv`).
+- `pysrc/juliacall/juliapkg.json` is tracked; restore its original contents after using the development copy for Python tests.
+
 ## Meta instructions
+- When testing an older Julia version, a local manifest generated by newer Julia can fail on stdlib dependencies. Use a temporary environment with `Pkg.develop(path=pwd()); Pkg.test("PythonCall")` to resolve dependencies for that Julia version.
+- CI caches Conda.jl build configuration without its root environment. Rebuild Conda after cache restore before PyCall is built; otherwise Julia 1.10 can fail before tests with "Path to conda environment is not valid".
 - When you discover environment quirks, false assumptions, process fixes, or any other generally useful info, update this AGENTS.md so future coding agents have the information.

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## Unreleased
+* Minimum supported Python version is now 3.11.
+
 ## 0.9.37 (2026-10-12)
 * Compatibility fix with Python 3.15 from conda-forge, which no longer bundles libpython.
 * Bug fixes.

CondaPkg.toml

@@ -9,7 +9,7 @@ version = "<=julia"
 
 [deps.python]
 build = "**cpython**"
-version = ">=3.10,!=3.14.0,!=3.14.1,<4"
+version = ">=3.11,!=3.14.0,!=3.14.1,<4"
 
 [deps.libpython]
 build = "**bundled-or-separate**"

README.md

@@ -14,7 +14,7 @@ Bringing [**Python®**](https://www.python.org/) and [**Julia**](https://juliala
 - Fast non-copying conversion of numeric arrays in either direction: modify Python arrays (e.g. `bytes`, `array.array`, `numpy.ndarray`) from Julia or Julia arrays from Python.
 - Helpful wrappers: interpret Python sequences, dictionaries, arrays, dataframes and IO streams as their Julia counterparts, and vice versa.
 - Beautiful stack-traces.
-- Supports modern systems: tested on Windows, MacOS and Linux; 64-bit; Julia 1.10 upwards and Python 3.10 upwards.
+- Supports modern systems: tested on Windows, MacOS and Linux; 64-bit; Julia 1.10 upwards and Python 3.11 upwards.
 
 ⭐ If you like this, a GitHub star would be lovely thank you. ⭐
 

docs/src/faq.md

@@ -112,7 +112,7 @@ np = pyimport("numpy")
 ## What versions of Python and Julia do you support?
 
 Each release of PythonCall and JuliaCall will support and require:
-- Any currently supported version of Python, [see here](https://devguide.python.org/versions/). Currently 3.10+.
+- Any currently supported version of Python, [see here](https://devguide.python.org/versions/). Currently 3.11+.
 - The current Julia LTS version and newer, [see here](https://julialang.org/downloads/#long_term_support_release). Currently 1.10+.
 
 Only the latest patch release within each minor version is supported.

docs/src/index.md

@@ -7,4 +7,4 @@ Bringing [**Python®**](https://www.python.org/) and [**Julia**](https://juliala
 - Fast non-copying conversion of numeric arrays in either direction: modify Python arrays (e.g. `bytes`, `array.array`, `numpy.ndarray`) from Julia or Julia arrays from Python.
 - Helpful wrappers: interpret Python sequences, dictionaries, arrays, dataframes and IO streams as their Julia counterparts, and vice versa.
 - Beautiful stack-traces.
-- Works anywhere: tested on Windows, MacOS and Linux; 64-bit; Julia 1.10 upwards and Python 3.10 upwards.
+- Works anywhere: tested on Windows, MacOS and Linux; 64-bit; Julia 1.10 upwards and Python 3.11 upwards.

pyproject.toml

@@ -12,7 +12,7 @@ classifiers = [
     "License :: OSI Approved :: MIT License",
     "Operating System :: OS Independent",
 ]
-requires-python = ">=3.10, <4"
+requires-python = ">=3.11, <4"
 dependencies = ["juliapkg >=0.1.27, <0.2"]
 
 [dependency-groups]

src/C/context.jl

@@ -323,8 +323,8 @@ function init_context()
         error("Cannot parse version from version string: $(repr(verstr))")
     end
     CTX.version = VersionNumber(vermatch.match)
-    v"3.10" ≤ CTX.version < v"4" || error(
-        "Only Python 3.10+ is supported, this is Python $(CTX.version) at $(CTX.exe_path===missing ? "unknown location" : CTX.exe_path).",
+    v"3.11" ≤ CTX.version < v"4" || error(
+        "Only Python 3.11+ is supported, this is Python $(CTX.version) at $(CTX.exe_path===missing ? "unknown location" : CTX.exe_path).",
     )
     CTX.is_free_threaded = occursin("free-threading build", verstr)