Include cxxbridge-cmd in Cargo.lock, check version consistency

This adds cxxbridge-cmd to Cargo.lock per
dtolnay/cxx#1407 (comment)

It adds an MSRV to `src/taskchampion-cpp/Cargo.toml` so that the
version of `Cargo.lock` is stil compatible with the MSRV.

It additionally adds a check of the Cargo metadata for all of the cxx*
versions agreeing.

.github/workflows/checks.yml

@@ -64,3 +64,19 @@ jobs:
         with:
           command: fmt
           args: --all -- --check
+
+  cargo-metadata:
+    runs-on: ubuntu-latest
+    name: "Cargo Metadata"
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          components: rustfmt
+          toolchain: stable
+          override: true
+
+      - name: "Check metadata"
+        run: ".github/workflows/metadata-check.sh"

.github/workflows/metadata-check.sh

@@ -0,0 +1,48 @@
+#! /bin/bash
+
+# Check the 'cargo metadata' for various requirements
+
+set -e
+
+META=$(mktemp)
+trap 'rm -rf -- "${META}"' EXIT
+
+cargo metadata --locked --format-version 1 > "${META}"
+
+get_version() {
+  local package="${1}"
+  jq -r '.packages[] | select(.name == "'"${package}"'") | .version' "${META}"
+}
+
+# check that the cxx packages all have the same version
+cxx_version=$(get_version "cxx")
+cxx_build_version=$(get_version "cxx-build")
+cxxbridge_cmd_version=$(get_version "cxx-build")
+cxxbridge_flags_version=$(get_version "cxxbridge-flags")
+cxxbridge_macro_version=$(get_version "cxxbridge-macro")
+
+ok=true
+echo "Found cxx version ${cxx_version}"
+if [ "${cxx_version}" != "${cxx_build_version}" ]; then
+  echo "Found differing cxx-build version ${cxx_build_version}"
+  ok = false
+fi
+if [ "${cxx_version}" != "${cxxbridge_cmd_version}" ]; then
+  echo "Found differing cxxbridge-cmd version ${cxxbridge_cmd_version}"
+  ok = false
+fi
+if [ "${cxx_version}" != "${cxxbridge_flags_version}" ]; then
+  echo "Found differing cxxbridge-flags version ${cxxbridge_flags_version}"
+  ok = false
+fi
+if [ "${cxx_version}" != "${cxxbridge_macro_version}" ]; then
+  echo "Found differing cxxbridge-macro version ${cxxbridge_macro_version}"
+  ok = false
+fi
+
+if ! $ok; then
+  echo "All cxx packages must be at the same version. Fix this in src/taskchampion-cpp/Cargo.toml."
+  exit 1
+else
+  echo "✓ All cxx packages are at the same version."
+fi

.github/workflows/tests.yaml

@@ -118,6 +118,7 @@ jobs:
           # If this version is old enough to cause errors, or older than the
           # TaskChampion MSRV, bump it to the MSRV of the currently-required
           # TaskChampion package; if necessary, bump that version as well.
+          # This should match the MSRV in `src/taskchampion-cpp/Cargo.toml`.
           toolchain: "1.73.0" # MSRV
           override: true
 

src/taskchampion-cpp/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.22)
+make_minimum_required (VERSION 3.22)
 
 OPTION(SYSTEM_CORROSION "Use system provided corrosion instead of vendored version" OFF)
 if(SYSTEM_CORROSION)

src/taskchampion-cpp/Cargo.toml

@@ -3,17 +3,28 @@ name = "taskchampion-lib"
 version = "0.1.0"
 edition = "2021"
 publish = false
+rust-version = "1.73.0"  # MSRV
 
 [lib]
 crate-type = ["staticlib"]
 
 [dependencies]
 taskchampion = "0.9.0"
-cxx = "1.0.124"
+# All three cxx* dependencies must have precisely the same version.
+cxx = "=1.0.124"
 
 [features]
 # use native CA roots, instead of bundled
 tls-native-roots = ["taskchampion/tls-native-roots"]
 
 [build-dependencies]
-cxx-build = "1.0"
+# All three cxx* dependencies must have precisely the same version.
+cxx-build = "=1.0.124"
+
+# Include cxxbridge-cmd in Cargo.lock along with the others. This gives a
+# warning "ignoring invalid dependency `cxxbridge-cmd` which is missing a lib
+# target" but this can be safely ignored.
+# See https://github.com/dtolnay/cxx/issues/1407#issuecomment-2509136343
+[target.'cfg(any())'.dependencies]
+# All three cxx* dependencies must have precisely the same version.
+cxxbridge-cmd = "=1.0.124"