Test minimal versions in CI with a pinned lockfile

.github/workflows/ci.yml

@@ -99,4 +99,5 @@ jobs:
       - uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
           toolchain: ${{ matrix.toolchain }}
+      - run: cp Cargo.lock.minimal Cargo.lock
       - run: cargo test --lib --bins ${{ matrix.features }}

Cargo.toml

@@ -20,7 +20,7 @@ syn = "2"
 quote = "1"
 proc-macro2 = "1"
 
-enum-ordinalize = { version = "4.2", default-features = false, features = ["derive"] }
+enum-ordinalize = { version = "4.2.1", default-features = false, features = ["derive"] }
 
 [dev-dependencies]
 syn = { version = "2", features = ["full"] }

maint/update-minimal-versions

@@ -0,0 +1,20 @@
+#! /bin/bash
+
+set -e
+set -o pipefail
+
+: "${CARGO:=cargo}"
+
+if test -e Cargo.lock.aside; then
+	rm -f Cargo.lock
+else
+	mv Cargo.lock Cargo.lock.aside
+fi
+
+$CARGO +nightly update  -Z minimal-versions
+
+# assert-eq-float has a too-relaxed dependency and only works with num-traits 0.2.1
+$CARGO update --precise=0.2.1 -p num-traits
+
+mv Cargo.lock Cargo.lock.minimal
+mv Cargo.lock.aside Cargo.lock