Wrap cargo-miri for rust-src

cargo-miri-wrapper.sh

@@ -0,0 +1,11 @@
+#!@bash@ -e
+src_dir="@out@/lib/rustlib/src/rust/library"
+if [[ ! -v XARGO_RUST_SRC ]]; then
+    if [[ ! -d "$src_dir" ]]; then
+        echo '`rust-src` is required by miri but not installed.' >&2
+        echo 'Please either install component `rust-src` or set `XARGO_RUST_SRC`.' >&2
+        exit 1
+    fi
+    export XARGO_RUST_SRC="$src_dir"
+fi
+exec -a "$0" "@miri@" "$@"

rust-overlay.nix

@@ -253,6 +253,16 @@ let
             cp --remove-destination "$(realpath -e $target)" $target
           fi
         done
+
+        if [ -e $out/bin/cargo-miri ]; then
+          cargo_miri=$(readlink $out/bin/cargo-miri)
+          cp -f ${./cargo-miri-wrapper.sh} $out/bin/cargo-miri
+          chmod +w $out/bin/cargo-miri
+          substituteInPlace $out/bin/cargo-miri \
+            --replace "@bash@" "${self.pkgs.bash}/bin/bash" \
+            --replace "@miri@" "$cargo_miri" \
+            --replace "@out@" "$out"
+        fi
       '';
 
       # Add the compiler as part of the propagated build inputs in order