Add a test for --features nighly on travis

Author: kngwyu

.travis.yml

@@ -16,23 +16,25 @@ jobs:
       python: "3.7"
     - name: Python 3.8
       python: "3.8"
+      # Run clippy and rustfmt
+      env: RUN_LINT=1
     - name: Python 3.9-dev
       python: "3.9-dev"
-    - name: Minimum nightly
+    - name: Nightly
       python: "3.7"
-      # Keep this synced up with build.rs and ensure that the nightly version does have clippy available
-      # https://static.rust-lang.org/dist/YYYY-MM-DD/clippy-nightly-x86_64-unknown-linux-gnu.tar.gz exists
-      env: TRAVIS_RUST_VERSION=nightly-2020-01-21
+      env: TRAVIS_RUST_VERSION=nightly FEATURES="nightly"
     - name: PyPy3.5 7.0 # Tested via anaconda PyPy (since travis's PyPy version is too old)
       python: "3.7"
       env: FEATURES="pypy" PATH="$PATH:/opt/anaconda/envs/pypy3/bin"
   allow_failures:
+    - name: Nightly
     - python: 3.9-dev
 
 env:
   global:
     - TRAVIS_RUST_VERSION=stable
     - RUST_BACKTRACE=1
+    - RUN_LINT=0
 
 before_install:
   - source ./ci/travis/setup.sh

ci/travis/setup.sh

@@ -7,7 +7,7 @@ set -e
 # Use profile=minimal here to skip installing clippy
 curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain=$TRAVIS_RUST_VERSION --profile=minimal -y
 export PATH=$PATH:$HOME/.cargo/bin
-if [ "$TRAVIS_JOB_NAME" = "Minimum nightly" ]; then
+if [[ $RUN_LINT == 1 ]]; then
     rustup component add clippy
     rustup component add rustfmt
 fi

ci/travis/test.sh

@@ -10,7 +10,7 @@ else
   PYTHON_SYS_EXECUTABLE="/opt/anaconda/envs/pypy3/bin/pypy3" cargo build;
 fi
 
-if [ "$TRAVIS_JOB_NAME" = "Minimum nightly" ]; then
+if [[ $RUN_LINT == 1 ]]; then
     pip install --pre black==19.3b0
     make lint
 fi

src/lib.rs

@@ -1,4 +1,4 @@
-#![cfg_attr(nightly, feature(specialization))]
+#![cfg_attr(feature = "nightly", feature(specialization))]
 #![allow(clippy::missing_safety_doc)] // FIXME (#698)
 
 //! Rust bindings to the Python interpreter.

tests/test_compile_error.rs

@@ -7,11 +7,7 @@ fn test_compile_errors() {
     t.compile_fail("tests/ui/missing_clone.rs");
     t.compile_fail("tests/ui/reject_generics.rs");
     t.compile_fail("tests/ui/wrong_aspyref_lifetimes.rs");
-    // Since the current minimum nightly(2020-01-20) has a different error message,
-    // we skip this test.
-    // TODO(kngwyu): Remove this `if` when we update minimum nightly.
-    if option_env!("TRAVIS_JOB_NAME") != Some("Minimum nightly") {
-        t.compile_fail("tests/ui/invalid_pymethod_names.rs");
-        t.compile_fail("tests/ui/static_ref.rs");
-    }
+    t.compile_fail("tests/ui/static_ref.rs");
+    #[cfg(not(feature = "nightly"))]
+    t.compile_fail("tests/ui/invalid_pymethod_names.rs");
 }

tests/test_datetime.rs

@@ -1,4 +1,3 @@
-use pyo3::ffi::*;
 use pyo3::prelude::*;
 use pyo3::types::IntoPyDict;