Missing cassert include

# Description

With Xcode 27, building deps on macOS 26 fails at the Python install
step with a segfault, and a libpython built with Xcode 27 crashes on
macOS 12–26 the first time anything calls `os.pipe()`, which every
plugin `subprocess` call does. The macOS 27 SDK declares `pipe2()` and
`dup3()` as macOS 27-only, and CPython 3.12 calls them without a runtime
check once configure finds them, so on older systems they resolve to
NULL. This keeps CPython on the `pipe()`/`dup2()` fallbacks it already
uses with older SDKs; upstream fixed it in 3.13+
([python/cpython#153711](https://github.com/python/cpython/issues/153711))
but not in 3.12.

No change for builds with Xcode 26 or older, or on Linux and Windows.

# Screenshots/Recordings/Graphs

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## Tests

Rebuilt deps with Xcode 27 on macOS 26.6: the Python install step now
completes, the installed libpython no longer imports `pipe2`/`dup3`, and
CPython's `test_os`, `test_subprocess` and `test_posix` pass, apart from
one test that needs `_testcapi`, which `--disable-test-modules` leaves
out. Running CPython's configure against the macOS 26.5 and 27.0 SDKs
gives a byte-identical `pyconfig.h` for 26.5 with and without this
change, and for 27.0 with it. The x86_64 cross-build path was configured
on arm64 to confirm both of its configure runs pick up the change.

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deps/python3/python3.cmake

@@ -151,6 +151,12 @@ elseif(APPLE)
     # the post-install -add_rpath below.
     set(_python_ldflags "${_python_arch_flags} -Wl,-headerpad_max_install_names")
 
+    # The macOS 27 SDK declares pipe2() and dup3() as available from macOS 27, so
+    # configure finds them and CPython 3.12 calls them without a runtime check.
+    # Below a macOS 27 deployment target they are weak-linked and resolve to NULL
+    # on older systems, where os.pipe() then segfaults -- in `make install`
+    # (compileall, ensurepip) and in the shipped app alike. Every configure below
+    # keeps the pipe()/dup2() fallbacks (python/cpython#153711).
     if(IS_CROSS_COMPILE)
         set(_python_build_tgt --build=${_python_build_arch}-apple-darwin --host=${_python_host_arch}-apple-darwin)
         set(_python_build_arch_flags "-arch ${_python_build_arch_flag} -mmacosx-version-min=${CMAKE_OSX_DEPLOYMENT_TARGET}")
@@ -174,7 +180,8 @@ elseif(APPLE)
                  --enable-shared \
                  --without-static-libpython \
                  --disable-test-modules \
-                 --build=${_python_build_arch}-apple-darwin && \
+                 --build=${_python_build_arch}-apple-darwin \
+                 ac_cv_func_pipe2=no ac_cv_func_dup3=no && \
              make -j${NPROC} python && \
              cd '<SOURCE_DIR>' && \
              env \
@@ -191,6 +198,7 @@ elseif(APPLE)
                  --without-static-libpython \
                  --with-openssl='${DESTDIR}' \
                  --disable-test-modules \
+                 ac_cv_func_pipe2=no ac_cv_func_dup3=no \
                  ${_python_build_tgt} \
                  --with-build-python='${_python_build_python}' \
                  py_cv_module__tkinter=n/a"
@@ -213,6 +221,8 @@ elseif(APPLE)
             --with-openssl=${DESTDIR}
             --disable-test-modules
             ${_python_build_tgt}
+            ac_cv_func_pipe2=no
+            ac_cv_func_dup3=no
             # Tcl/Tk 9.0 (e.g. from Homebrew) is incompatible with CPython 3.12's
             # _tkinter; OrcaSlicer's embedded Python does not need tkinter anyway.
             py_cv_module__tkinter=n/a

src/libslic3r/Color.hpp

@@ -6,6 +6,8 @@
 #include <array>
 #include <algorithm>
 
+#include <cassert>
+
 namespace Slic3r {
 using RGB = std::array<float, 3>;
 using RGBA = std::array<float, 4>;

tests/slic3rutils/slic3rutils_tests_main.cpp

@@ -1,6 +1,39 @@
 #include <catch2/catch_all.hpp>
 
 #include "slic3r/Utils/Http.hpp"
+#include "slic3r/Utils/OrcaCloudServiceAgent.hpp"
+
+namespace {
+
+nlohmann::json flat_session_json(const nlohmann::json& fields)
+{
+    nlohmann::json session = {
+        {"access_token", "test-token"},
+        {"user_id", "test-user-id"}
+    };
+    session.update(fields);
+    return session;
+}
+
+nlohmann::json nested_session_json(const nlohmann::json& metadata)
+{
+    return {
+        {"access_token", "test-token"},
+        {"user", {
+            {"id", "test-user-id"},
+            {"user_metadata", metadata}
+        }}
+    };
+}
+
+std::string resolved_display_name(const nlohmann::json& session)
+{
+    Slic3r::OrcaCloudServiceAgent agent("");
+    REQUIRE(agent.set_user_session(session, false));
+    return agent.get_user_nickname();
+}
+
+} // namespace
 
 TEST_CASE("Check SSL certificates paths", "[Http][NotWorking]") {
     
@@ -20,6 +53,62 @@ TEST_CASE("Check SSL certificates paths", "[Http][NotWorking]") {
     REQUIRE(status == 200);
 }
 
+TEST_CASE("Orca cloud flat session resolves display name consistently", "[OrcaCloudServiceAgent]")
+{
+    CHECK(resolved_display_name(flat_session_json({
+        {"username", "orca_username"},
+        {"display_name", "Display Name"},
+        {"nickname", "Nickname"}
+    })) == "Display Name");
+
+    CHECK(resolved_display_name(flat_session_json({
+        {"username", "orca_username"},
+        {"nickname", "Nickname"}
+    })) == "Nickname");
+
+    CHECK(resolved_display_name(flat_session_json({
+        {"username", "orca_username"},
+        {"full_name", "Full Name"}
+    })) == "Full Name");
+
+    CHECK(resolved_display_name(flat_session_json({
+        {"username", "orca_username"},
+        {"name", "Provider Name"}
+    })) == "Provider Name");
+
+    CHECK(resolved_display_name(flat_session_json({
+        {"username", "orca_username"}
+    })) == "orca_username");
+}
+
+TEST_CASE("Orca cloud nested session resolves display name consistently", "[OrcaCloudServiceAgent]")
+{
+    CHECK(resolved_display_name(nested_session_json({
+        {"username", "orca_username"},
+        {"display_name", "Display Name"},
+        {"nickname", "Nickname"}
+    })) == "Display Name");
+
+    CHECK(resolved_display_name(nested_session_json({
+        {"username", "orca_username"},
+        {"nickname", "Nickname"}
+    })) == "Nickname");
+
+    CHECK(resolved_display_name(nested_session_json({
+        {"username", "orca_username"},
+        {"full_name", "Full Name"}
+    })) == "Full Name");
+
+    CHECK(resolved_display_name(nested_session_json({
+        {"username", "orca_username"},
+        {"name", "Provider Name"}
+    })) == "Provider Name");
+
+    CHECK(resolved_display_name(nested_session_json({
+        {"username", "orca_username"}
+    })) == "orca_username");
+}
+
 TEST_CASE("Http digest authentication", "[Http][NotWorking]") {
     Slic3r::Http g = Slic3r::Http::get("https://httpbingo.org/digest-auth/auth/guest/guest");
 

tests/slic3rutils/test_orca_cloud_agent.cpp

@@ -27,37 +27,6 @@ std::unique_ptr<OrcaCloudServiceAgent> make_file_backed_agent(const fs::path& di
 
 fs::path secret_file(const fs::path& dir) { return dir / secret_constants::USER_SECRET_FILENAME; }
 
-nlohmann::json flat_session_json(const nlohmann::json& fields)
-{
-    nlohmann::json session = {
-        {"access_token", "test-token"},
-        {"user_id", "test-user-id"}
-    };
-    session.update(fields);
-    return session;
-}
-
-nlohmann::json nested_session_json(const nlohmann::json& metadata)
-{
-    return {
-        {"access_token", "test-token"},
-        {"user", {
-            {"id", "test-user-id"},
-            {"user_metadata", metadata}
-        }}
-    };
-}
-
-// set_user_session() persists the session, so it goes to a throwaway token file rather than the
-// system keychain of whoever runs the tests.
-std::string resolved_display_name(const nlohmann::json& session)
-{
-    ScopedTemporaryDir dir("orca-secret");
-    auto               agent = make_file_backed_agent(dir.path());
-    REQUIRE(agent->set_user_session(session, false));
-    return agent->get_user_nickname();
-}
-
 } // namespace
 
 TEST_CASE("Logging out removes the secret this instance saved", "[OrcaCloudServiceAgent]")
@@ -115,59 +84,3 @@ TEST_CASE("Logging out leaves a secret this instance could not read alone", "[Or
     agent->user_logout(false);
     CHECK(fs::exists(secret_file(dir.path())));
 }
-
-TEST_CASE("Orca cloud flat session resolves display name consistently", "[OrcaCloudServiceAgent]")
-{
-    CHECK(resolved_display_name(flat_session_json({
-        {"username", "orca_username"},
-        {"display_name", "Display Name"},
-        {"nickname", "Nickname"}
-    })) == "Display Name");
-
-    CHECK(resolved_display_name(flat_session_json({
-        {"username", "orca_username"},
-        {"nickname", "Nickname"}
-    })) == "Nickname");
-
-    CHECK(resolved_display_name(flat_session_json({
-        {"username", "orca_username"},
-        {"full_name", "Full Name"}
-    })) == "Full Name");
-
-    CHECK(resolved_display_name(flat_session_json({
-        {"username", "orca_username"},
-        {"name", "Provider Name"}
-    })) == "Provider Name");
-
-    CHECK(resolved_display_name(flat_session_json({
-        {"username", "orca_username"}
-    })) == "orca_username");
-}
-
-TEST_CASE("Orca cloud nested session resolves display name consistently", "[OrcaCloudServiceAgent]")
-{
-    CHECK(resolved_display_name(nested_session_json({
-        {"username", "orca_username"},
-        {"display_name", "Display Name"},
-        {"nickname", "Nickname"}
-    })) == "Display Name");
-
-    CHECK(resolved_display_name(nested_session_json({
-        {"username", "orca_username"},
-        {"nickname", "Nickname"}
-    })) == "Nickname");
-
-    CHECK(resolved_display_name(nested_session_json({
-        {"username", "orca_username"},
-        {"full_name", "Full Name"}
-    })) == "Full Name");
-
-    CHECK(resolved_display_name(nested_session_json({
-        {"username", "orca_username"},
-        {"name", "Provider Name"}
-    })) == "Provider Name");
-
-    CHECK(resolved_display_name(nested_session_json({
-        {"username", "orca_username"}
-    })) == "orca_username");
-}