ci: switch to ui-test instead of trybuild

.gitattributes

@@ -0,0 +1 @@
+* text=auto eol=lf

.github/workflows/build.yml

@@ -98,8 +98,8 @@ jobs:
         run: nox -s set-msrv-package-versions
 
       - if: inputs.rust != 'stable'
-        name: Ignore changed error messages when using trybuild
-        run: echo "TRYBUILD=overwrite" >> "$GITHUB_ENV"
+        name: Ignore changed error messages for ui tests (still run for coverage)
+        run: echo "UI_TEST=ignore" >> "$GITHUB_ENV"
 
       - uses: dorny/paths-filter@v4
         if: ${{ inputs.rust == 'stable' && !startsWith(inputs.python-version, 'graalpy') }}

.github/workflows/ci.yml

@@ -378,7 +378,7 @@ jobs:
     env:
       CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUNNER: valgrind --leak-check=no --error-exitcode=1
       RUST_BACKTRACE: 1
-      TRYBUILD: overwrite
+      UI_TEST: skip
 
   careful:
     if: ${{ contains(github.event.pull_request.labels.*.name, 'CI-build-full') || github.event_name != 'pull_request' }}
@@ -400,7 +400,7 @@ jobs:
       - run: nox -s test-rust -- careful skip-full
     env:
       RUST_BACKTRACE: 1
-      TRYBUILD: overwrite
+      UI_TEST: skip
 
   docsrs:
     if: ${{ contains(github.event.pull_request.labels.*.name, 'CI-build-full') || github.event_name != 'pull_request' }}

Cargo.toml

@@ -69,7 +69,6 @@ portable-atomic = "1.0"
 assert_approx_eq = "1.1.0"
 chrono = "0.4.25"
 chrono-tz = ">= 0.10, < 0.11"
-trybuild = ">=1.0.115"
 proptest = { version = "1.0", default-features = false, features = ["std"] }
 send_wrapper = "0.6"
 serde = { version = "1.0", features = ["derive"] }
@@ -80,6 +79,10 @@ tempfile = "3.12.0"
 static_assertions = "1.1.0"
 uuid = { version = "1.10.0", features = ["v4"] }
 parking_lot = { version = "0.12.3", features = ["arc_lock"] }
+ui_test = "0.30.4"
+regex = "1.12.3"
+[target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
+ctrlc = "3.5.2"
 
 [build-dependencies]
 pyo3-build-config = { path = "pyo3-build-config", version = "=0.28.3", features = ["resolve-config"] }
@@ -180,6 +183,7 @@ members = [
     "pyo3-macros",
     "pyo3-macros-backend",
     "pyo3-introspection",
+    "tests/ui/base",
     "pytests",
     "examples",
 ]
@@ -222,3 +226,8 @@ bare_urls = "warn"
 
 [lints]
 workspace = true
+
+[[test]]
+name = "test_compile_error"
+path = "tests/test_compile_error.rs"
+harness = false

Contributing.md

@@ -45,7 +45,7 @@ Use  `nox -l` to list the full set of subcommands you can run.
 
 #### UI Tests
 
-PyO3 uses [`trybuild`][trybuild] to develop UI tests to capture error messages from the Rust compiler for some of the macro functionality.
+PyO3 uses [`ui_test`][ui_test] to develop UI tests to capture error messages from the Rust compiler for some of the macro functionality.
 
 The Rust compiler's error output differs depending on whether the `rust-src` component is installed. PyO3's CI has `rust-src` installed, so you need it locally for your UI test output to match:
 
@@ -265,4 +265,4 @@ In the meanwhile, some of our maintainers have personal GitHub sponsorship pages
 [lychee]: https://github.com/lycheeverse/lychee
 [nox]: https://github.com/theacodes/nox
 [pipx]: https://pipx.pypa.io/stable/
-[trybuild]: https://github.com/dtolnay/trybuild
+[ui_test]: https://github.com/oli-obk/ui_test

noxfile.py

@@ -1418,7 +1418,7 @@ def check_feature_powerset(session: nox.Session):
 @nox.session(name="update-ui-tests", venv_backend="none")
 def update_ui_tests(session: nox.Session):
     env = os.environ.copy()
-    env["TRYBUILD"] = "overwrite"
+    env["UI_TEST"] = "bless"
     command = ["test", "--test", "test_compile_error"]
     _run_cargo(session, *command, env=env)
     _run_cargo(session, *command, "--features=full", env=env)