Pin nightly toolchain used for miri job

dtolnay · dtolnay · commit e1685084319a · 2025-05-17T22:49:37.000+02:00
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -78,6 +78,8 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@miri
+        with:
+          toolchain: nightly-2025-05-16  # https://github.com/rust-lang/miri/issues/4323
       - run: cargo miri setup
       - run: cargo miri test
         env:
