Support Erlang/OTP 28 and 29

Validate build and the full Common Test suite on OTP 28 and 29 across
Python 3.12-3.14. Set minimum_otp_vsn to 28 and update CI to test both
releases with rebar3 3.25.

Replace deprecated prefix-catch cleanup calls with try/catch to clear the
new OTP 29 default warning; behavior is unchanged.

Author: benoitc

.github/workflows/ci.yml

@@ -15,25 +15,35 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          # Linux with different OTP/Python combinations
+          # Linux - OTP 28
           - os: ubuntu-24.04
-            otp: "27.0"
+            otp: "28"
             python: "3.12"
           - os: ubuntu-24.04
-            otp: "27.0"
+            otp: "28"
             python: "3.13"
           - os: ubuntu-24.04
-            otp: "27.0"
+            otp: "28"
             python: "3.14"
-          # macOS
+          # Linux - OTP 29
+          - os: ubuntu-24.04
+            otp: "29"
+            python: "3.12"
+          - os: ubuntu-24.04
+            otp: "29"
+            python: "3.13"
+          - os: ubuntu-24.04
+            otp: "29"
+            python: "3.14"
+          # macOS (brew installs the latest OTP)
           - os: macos-15
-            otp: "27"
+            otp: "29"
             python: "3.12"
           - os: macos-15
-            otp: "27"
+            otp: "29"
             python: "3.13"
           - os: macos-15
-            otp: "27"
+            otp: "29"
             python: "3.14"
 
     steps:
@@ -50,7 +60,7 @@ jobs:
         uses: erlef/setup-beam@v1
         with:
           otp-version: ${{ matrix.otp }}
-          rebar3-version: "3.24"
+          rebar3-version: "3.25"
 
       - name: Set up Erlang (macOS)
         if: startsWith(matrix.os, 'macos')
@@ -139,7 +149,7 @@ jobs:
             python${{ matrix.python }} --version
 
             # Build with rebar3
-            fetch https://github.com/erlang/rebar3/releases/download/3.24.0/rebar3 -o rebar3
+            fetch https://github.com/erlang/rebar3/releases/download/3.25.0/rebar3 -o rebar3
             chmod +x rebar3
 
             # Compile and test (uses CMake-based build)
@@ -160,8 +170,8 @@ jobs:
       - name: Set up Erlang
         uses: erlef/setup-beam@v1
         with:
-          otp-version: "27.0"
-          rebar3-version: "3.24"
+          otp-version: "29"
+          rebar3-version: "3.25"
 
       - name: Set up free-threaded Python
         uses: actions/setup-python@v5
@@ -234,8 +244,8 @@ jobs:
       - name: Set up Erlang
         uses: erlef/setup-beam@v1
         with:
-          otp-version: "27.0"
-          rebar3-version: "3.24"
+          otp-version: "29"
+          rebar3-version: "3.25"
 
       - name: Install dependencies
         run: |
@@ -280,8 +290,8 @@ jobs:
       - name: Set up Erlang
         uses: erlef/setup-beam@v1
         with:
-          otp-version: "27.0"
-          rebar3-version: "3.24"
+          otp-version: "29"
+          rebar3-version: "3.25"
 
       - name: Set up Python
         uses: actions/setup-python@v5
@@ -313,8 +323,8 @@ jobs:
       - name: Set up Erlang
         uses: erlef/setup-beam@v1
         with:
-          otp-version: "27.0"
-          rebar3-version: "3.24"
+          otp-version: "29"
+          rebar3-version: "3.25"
 
       - name: Set up Python
         uses: actions/setup-python@v5

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Changelog
 
+## Unreleased
+
+### Changed
+
+- **Support Erlang/OTP 28 and 29** - Validated builds and the full Common Test
+  suite on OTP 28 and 29. Minimum supported OTP is now 28 (`minimum_otp_vsn`).
+  CI tests OTP 28 and 29 across Python 3.12/3.13/3.14.
+- Replaced deprecated `catch Expr` cleanup calls with `try ... catch ... end`
+  to silence the new OTP 29 default warning; behavior is unchanged.
+
 ## 3.0.0 (2026-05-03)
 
 ### Breaking Changes

README.md

@@ -37,7 +37,7 @@ Key features:
 
 ## Requirements
 
-- Erlang/OTP 27+
+- Erlang/OTP 28+ (tested on OTP 28 and 29)
 - Python 3.12+ (3.13+ for free-threading)
 - C compiler (gcc, clang)
 

docs/scalability.md

@@ -609,6 +609,24 @@ The `PERF_BUILD` option enables:
 {ok, 2}
 ```
 
+### Erlang/OTP Version
+
+erlang_python is built and tested on **Erlang/OTP 28 and 29** (minimum OTP 28).
+The heavy lifting happens in the C NIF, so the BEAM-side glue is light, but newer
+OTP releases still help for free:
+
+- **OTP 29 JIT and scheduler improvements** apply to the Erlang side (routing,
+  context bookkeeping, callback dispatch) with no code change. Just run on OTP 29.
+- **Consistent map iteration order** is now guaranteed across map operations in
+  OTP 29. The router and state modules do not depend on iteration order, so this
+  changes nothing here, but it removes a class of subtle bugs if you build on top.
+- **Building the NIF stays the same** across OTP 28/29 (NIF API 2.18); no version
+  guards are needed in `c_src`.
+
+For doc-example testing, OTP 29 ships `ct_doctest`. This project keeps its own
+`scripts/lint_doc_snippets.escript` because that linter also validates the Python
+blocks in the docs, which `ct_doctest` does not cover.
+
 ## See Also
 
 - [Getting Started](getting-started.md) - Basic usage

rebar.config

@@ -1,5 +1,7 @@
 {erl_opts, [debug_info]}.
 
+{minimum_otp_vsn, "28"}.
+
 {xref_checks, [
     undefined_function_calls,
     undefined_functions,

src/erlang_python_app.erl

@@ -25,6 +25,6 @@ start(_StartType, _StartArgs) ->
 stop(_State) ->
     %% Stop pools before application shutdown to ensure proper cleanup
     %% of subinterpreters before NIF resources are garbage collected
-    catch py_context_router:stop_pool(io),
-    catch py_context_router:stop_pool(default),
+    try py_context_router:stop_pool(io) catch _:_ -> ok end,
+    try py_context_router:stop_pool(default) catch _:_ -> ok end,
     ok.

src/py_context.erl

@@ -651,12 +651,12 @@ terminate(_Reason, #state{ref = Ref, event_state = EventState, callback_handler
     %% Stop the event worker first (if it exists and is still alive)
     case EventState of
         #{worker_pid := WorkerPid} ->
-            catch gen_server:stop(WorkerPid, normal, 5000);
+            try gen_server:stop(WorkerPid, normal, 5000) catch _:_ -> ok end;
         _ ->
             ok
     end,
     %% Destroy the Python context
-    catch py_nif:context_destroy(Ref),
+    try py_nif:context_destroy(Ref) catch _:_ -> ok end,
     ok.
 
 %% ============================================================================

src/py_context_router.erl

@@ -355,7 +355,7 @@ stop_pool(Pool) when is_atom(Pool) ->
         Contexts ->
             lists:foreach(
                 fun(Ctx) ->
-                    catch py_context_sup:stop_context(Ctx)
+                    try py_context_sup:stop_context(Ctx) catch _:_ -> ok end
                 end,
                 Contexts
             )
@@ -365,12 +365,12 @@ stop_pool(Pool) when is_atom(Pool) ->
     Size = persistent_term:get(?POOL_SIZE_KEY(Pool), 0),
     lists:foreach(
         fun(N) ->
-            catch persistent_term:erase(?POOL_CONTEXT_KEY(Pool, N))
+            try persistent_term:erase(?POOL_CONTEXT_KEY(Pool, N)) catch _:_ -> ok end
         end,
         lists:seq(1, Size)
     ),
-    catch persistent_term:erase(?POOL_SIZE_KEY(Pool)),
-    catch persistent_term:erase(?POOL_CONTEXTS_KEY(Pool)),
+    try persistent_term:erase(?POOL_SIZE_KEY(Pool)) catch _:_ -> ok end,
+    try persistent_term:erase(?POOL_CONTEXTS_KEY(Pool)) catch _:_ -> ok end,
     ok.
 
 %% @doc Check if a pool has been started and is still alive.

src/py_event_loop.erl

@@ -442,7 +442,7 @@ import sys, asyncio
 if sys.version_info < (3, 14):
     asyncio.set_event_loop_policy(None)
 ">>,
-    catch py:exec(Code),
+    try py:exec(Code) catch _:_ -> ok end,
     ok.
 
 code_change(_OldVsn, State, _Extra) ->

src/py_event_loop_pool.erl

@@ -510,7 +510,7 @@ handle_info({'DOWN', MonRef, process, Pid, _Reason}, State) ->
                 case SessionPid =:= Pid andalso SessionMonRef =:= MonRef of
                     true ->
                         %% Destroy session in worker
-                        catch py_nif:owngil_destroy_session(WorkerId, HandleId),
+                        try py_nif:owngil_destroy_session(WorkerId, HandleId) catch _:_ -> ok end,
                         %% Remove from ETS
                         ets:delete(Tid, Key);
                     false ->
@@ -531,15 +531,15 @@ terminate(_Reason, State) ->
         Tid ->
             %% Destroy all sessions
             ets:foldl(fun(#owngil_session{worker_id = WorkerId, handle_id = HandleId}, _) ->
-                catch py_nif:owngil_destroy_session(WorkerId, HandleId),
+                try py_nif:owngil_destroy_session(WorkerId, HandleId) catch _:_ -> ok end,
                 ok
             end, ok, Tid),
-            catch ets:delete(Tid)
+            try ets:delete(Tid) catch _:_ -> ok end
     end,
 
     %% Stop OWN_GIL thread pool if it was started
     case State#state.owngil_enabled of
-        true -> catch py_nif:subinterp_thread_pool_stop();
+        true -> try py_nif:subinterp_thread_pool_stop() catch _:_ -> ok end;
         false -> ok
     end,
 
@@ -548,15 +548,15 @@ terminate(_Reason, State) ->
         {} -> ok;
         Loops ->
             lists:foreach(fun({LoopRef, WorkerPid}) ->
-                catch py_event_worker:stop(WorkerPid),
-                catch py_nif:event_loop_destroy(LoopRef)
+                try py_event_worker:stop(WorkerPid) catch _:_ -> ok end,
+                try py_nif:event_loop_destroy(LoopRef) catch _:_ -> ok end
             end, tuple_to_list(Loops))
     end,
 
-    catch persistent_term:erase(?PT_LOOPS),
-    catch persistent_term:erase(?PT_NUM_LOOPS),
-    catch persistent_term:erase(?PT_OWNGIL_ENABLED),
-    catch persistent_term:erase(?PT_SESSIONS),
+    try persistent_term:erase(?PT_LOOPS) catch _:_ -> ok end,
+    try persistent_term:erase(?PT_NUM_LOOPS) catch _:_ -> ok end,
+    try persistent_term:erase(?PT_OWNGIL_ENABLED) catch _:_ -> ok end,
+    try persistent_term:erase(?PT_SESSIONS) catch _:_ -> ok end,
     ok.
 
 %%% ============================================================================
@@ -638,7 +638,7 @@ create_session(Tid, Pid, LoopIdx) ->
                 false ->
                     %% Another process created the session first, destroy ours
                     erlang:demonitor(MonRef, [flush]),
-                    catch py_nif:owngil_destroy_session(WorkerId, HandleId),
+                    try py_nif:owngil_destroy_session(WorkerId, HandleId) catch _:_ -> ok end,
                     %% Retry lookup
                     case ets:lookup(Tid, {Pid, LoopIdx}) of
                         [#owngil_session{worker_id = W, handle_id = H}] ->