update Miri CI config

.github/workflows/ci.yml

@@ -51,6 +51,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - name: Miri
-        run: ci/miri.sh
-
+      - name: Install Miri
+        run: |
+          rustup toolchain install nightly --component miri
+          rustup override set nightly
+          cargo miri setup
+      - name: Test with Miri
+        run: cargo miri test

ci/miri.sh

@@ -1,15 +0,0 @@
-#!/bin/sh
-
-set -ex
-
-export CARGO_NET_RETRY=5
-export CARGO_NET_TIMEOUT=10
-
-MIRI_NIGHTLY=nightly-$(curl -s https://rust-lang.github.io/rustup-components-history/x86_64-unknown-linux-gnu/miri)
-echo "Installing latest nightly with Miri: $MIRI_NIGHTLY"
-rustup default "$MIRI_NIGHTLY"
-
-rustup component add miri
-cargo miri setup
-
-cargo miri test