diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 6e6dc0f4..4769e435 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -8,45 +8,69 @@ on:
 name: Continuous integration
 
 jobs:
+  Prepare:
+    runs-on: ubuntu-latest
+    outputs:
+      crates: ${{ steps.get_matrix.outputs.crates }}
+      deps: ${{ steps.get_matrix.outputs.deps }}
+    steps:
+      - name: Checkout Crate
+        uses: actions/checkout@v4
+      - name: Prepare tests
+        id: get_matrix
+        run: contrib/get_matrix.sh
+
   Stable:
+    needs: Prepare
     name: Test - stable toolchain
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
+      matrix:
+        crate: ${{ fromJson(needs.Prepare.outputs.crates) }}
+        dep: ${{ fromJson(needs.Prepare.outputs.deps) }}
+        task: [test, docs, feature_matrix, dup_deps]
     steps:
       - name: Checkout Crate
         uses: actions/checkout@v4
       - name: Checkout Toolchain
         # https://github.com/dtolnay/rust-toolchain
         uses: dtolnay/rust-toolchain@stable
+      - name: Set dependencies
+        run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
       - name: Running test script
-        env:
-          AS_DEPENDENCY: false
-          DO_DOCS: true
-          DO_FEATURE_MATRIX: true
-          DO_SCHEMARS_TESTS: true # Currently only used in hashes crate.
-        run: ./contrib/test.sh
+        run: ./contrib/run_task.sh ${{ matrix.crate }} ${{ matrix.task }}
 
   Beta:
+    needs: Prepare
     name: Test - beta toolchain
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
+      matrix:
+        crate: ${{ fromJson(needs.Prepare.outputs.crates) }}
+        dep: ${{ fromJson(needs.Prepare.outputs.deps) }}
+        task: [test]
     steps:
       - name: Checkout Crate
         uses: actions/checkout@v4
       - name: Checkout Toolchain
         uses: dtolnay/rust-toolchain@beta
+      - name: Set dependencies
+        run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
       - name: Running test script
-        env:
-          AS_DEPENDENCY: false
-        run: ./contrib/test.sh
+        run: ./contrib/run_task.sh ${{ matrix.crate }} ${{ matrix.task }}
 
   Nightly:
+    needs: Prepare
     name: Test - nightly toolchain
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
+      matrix:
+        crate: ${{ fromJson(needs.Prepare.outputs.crates) }}
+        dep: ${{ fromJson(needs.Prepare.outputs.deps) }}
+        task: [test, lint, bench, docsrs]
     steps:
       - name: Checkout Crate
         uses: actions/checkout@v4
@@ -54,20 +78,21 @@ jobs:
         uses: dtolnay/rust-toolchain@nightly
       - name: Install clippy
         run: rustup component add clippy
+      - name: Set dependencies
+        run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
       - name: Running test script
-        env:
-          DO_LINT: true
-          DO_FMT: false
-          DO_BENCH: true
-          AS_DEPENDENCY: false
-          DO_DOCSRS: true
-        run: ./contrib/test.sh
+        run: ./contrib/run_task.sh ${{ matrix.crate }} ${{ matrix.task }}
 
   MSRV:
+    needs: Prepare
     name: Test - 1.56.1 toolchain
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
+      matrix:
+        crate: ${{ fromJson(needs.Prepare.outputs.crates) }}
+        dep: ${{ fromJson(needs.Prepare.outputs.deps) }}
+        task: [test, feature_matrix]
     steps:
       - name: Checkout Crate
         uses: actions/checkout@v4
@@ -75,10 +100,10 @@ jobs:
         uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: "1.56.1"
+      - name: Set dependencies
+        run: cp Cargo-${{ matrix.dep }}.lock Cargo.lock
       - name: Running test script
-        env:
-          DO_FEATURE_MATRIX: true
-        run: ./contrib/test.sh
+        run: ./contrib/run_task.sh ${{ matrix.crate }} ${{ matrix.task }}
 
   Arch32bit:
     name: Test 32-bit version
@@ -137,8 +162,15 @@ jobs:
         run: cd hashes/embedded && cargo run --target thumbv7m-none-eabi --features=alloc
 
   ASAN:
+    needs: Prepare
     name: Address sanitizer     # hashes crate only.
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        crate: [hashes]
+        dep: ${{ fromJson(needs.Prepare.outputs.deps) }}
+        task: [asan]
     steps:
       - name: Checkout Crate
         uses: actions/checkout@v4
@@ -147,22 +179,43 @@ jobs:
       - name: Install src
         run: rustup component add rust-src
       - name: Running address sanitizer
-        env:
-          DO_ASAN: true
-        run: cd hashes && ./contrib/test.sh
+        run: ./contrib/run_task.sh ${{ matrix.crate }} ${{ matrix.task }}
 
   WASM:
+    needs: Prepare
     name: WebAssembly Build # hashes crate only.
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        crate: [hashes]
+        dep: ${{ fromJson(needs.Prepare.outputs.deps) }}
+        task: [wasm]
     steps:
       - name: Checkout Crate
         uses: actions/checkout@v4
       - name: Checkout Toolchain
         uses: dtolnay/rust-toolchain@stable
       - name: Running WASM build
-        env:
-          DO_WASM: true
-        run: cd hashes && ./contrib/test.sh
+        run: ./contrib/run_task.sh ${{ matrix.crate }} ${{ matrix.task }}
+
+  Schemars:
+    needs: Prepare
+    name: Schemars
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        crate: [hashes]
+        dep: ${{ fromJson(needs.Prepare.outputs.deps) }}
+        task: [schemars]
+    steps:
+      - name: Checkout Crate
+        uses: actions/checkout@v4
+      - name: Checkout Toolchain
+        uses: dtolnay/rust-toolchain@stable
+      - name: Running schemars test
+        run: ./contrib/run_task.sh ${{ matrix.crate }} ${{ matrix.task }}
 
   Kani:
     runs-on: ubuntu-20.04
diff --git a/bitcoin/contrib/extra_tests.sh b/bitcoin/contrib/extra_tests.sh
new file mode 100755
index 00000000..d4c785c6
--- /dev/null
+++ b/bitcoin/contrib/extra_tests.sh
@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+set -ex
+
+cargo run --locked --example bip32 7934c09359b234e076b9fa5a1abfd38e3dc2a9939745b7cc3c22a48d831d14bd
+cargo run --locked --no-default-features --example bip32 7934c09359b234e076b9fa5a1abfd38e3dc2a9939745b7cc3c22a48d831d14bd
diff --git a/bitcoin/contrib/test_vars.sh b/bitcoin/contrib/test_vars.sh
new file mode 100644
index 00000000..6cb6ddb3
--- /dev/null
+++ b/bitcoin/contrib/test_vars.sh
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+# Test all these features with "std" enabled.
+FEATURES_WITH_STD="rand-std serde secp-recovery bitcoinconsensus-std base64 ordered"
+
+# Test all these features without "std" or "alloc" enabled.
+FEATURES_WITHOUT_STD="rand serde secp-recovery bitcoinconsensus base64 ordered"
+
+# Run and lint these examples.
+EXAMPLES="ecdsa-psbt:std,bitcoinconsensus sign-tx-segwit-v0:rand-std sign-tx-taproot:rand-std taproot-psbt:bitcoinconsensus,rand-std"
diff --git a/contrib/get_matrix.sh b/contrib/get_matrix.sh
new file mode 100755
index 00000000..d72a865b
--- /dev/null
+++ b/contrib/get_matrix.sh
@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+. contrib/test_vars.sh
+
+crates="`cargo metadata --no-deps --format-version 1 | jq -c '.packages | map(.manifest_path | rtrimstr("/Cargo.toml") | ltrimstr("'$PWD'/"))'`"
+deps="`echo -n $DEPS | jq -R -c 'split(" ")'`"
+# debug
+echo "$crates"
+echo "$deps"
+
+echo "crates=$crates" >> $GITHUB_OUTPUT
+echo "deps=$deps" >> $GITHUB_OUTPUT
diff --git a/contrib/run_task.sh b/contrib/run_task.sh
new file mode 100755
index 00000000..c3a622a3
--- /dev/null
+++ b/contrib/run_task.sh
@@ -0,0 +1,229 @@
+#!/bin/env bash
+
+set -ex
+
+# Make all cargo invocations verbose.
+export CARGO_TERM_VERBOSE=true
+
+cargo --version
+rustc --version
+
+main() {
+    crate="$1"
+    task="$2"
+
+    cd "$crate"
+
+    # Building the fuzz crate is more-or-less just a sanity check.
+    if [ "$crate" == "fuzz" ]
+    then
+        cargo --locked build
+        exit 0
+    fi
+
+    # Every crate must define EXAMPLES.
+    . contrib/test_vars.sh || exit 1
+
+    case $task in
+	test)
+	    do_test
+	    ;;
+
+	feature_matrix)
+	    do_feature_matrix
+	    ;;
+
+	lint)
+	    do_lint
+	    ;;
+
+	dup_deps)
+	    do_dup_deps
+	    ;;
+
+	docs)
+            build_docs_with_stable_toolchain
+	    ;;
+
+	docsrs)
+            build_docs_with_nightly_toolchain
+	    ;;
+
+	wasm)
+	    do_wasm
+	    ;;
+
+	asan)
+	    do_asan
+	    ;;
+
+	bench)
+	    do_bench
+	    ;;
+
+	schemars)
+	    do_schemars
+	    ;;
+	*)
+	    echo "Error: unknown task $task" >&2
+	    exit 1
+	    ;;
+    esac
+}
+
+do_test() {
+    # Use the current (recent/minimal) lock file.
+    local cargo="cargo --locked"
+
+    # Defaults / sanity checks
+    $cargo build
+    $cargo test
+
+    for example in $EXAMPLES; do
+	name="$(echo "$example" | cut -d ':' -f 1)"
+	features="$(echo "$example" | cut -d ':' -f 2)"
+	$cargo run --example "$name" --features="$features"
+    done
+
+    if [ -e ./contrib/extra_tests.sh ];
+    then
+	./contrib/extra_tests.sh
+    fi
+}
+
+# Each crate defines its own feature matrix test so feature combinations
+# can be better controlled.
+do_feature_matrix() {
+    local cargo="cargo --locked"
+
+    $cargo build --no-default-features
+    $cargo test --no-default-features
+
+    # All crates have a "std" feature.
+    loop_features "std" "$FEATURES_WITH_STD"
+
+    # All but `bitcoin` crate have an "alloc" feature, this tests it
+    # along with any other features that should work with "std".
+    if [ -n "$FEATURES_WITHOUT_STD" ]
+       then
+           loop_features "" "$FEATURES_WITHOUT_STD"
+    fi
+}
+
+# Build with each feature as well as all combinations of two features.
+#
+# Usage: loop_features "std" "this-feature that-feature other"
+loop_features() {
+    local use="$1"
+    local features="$2"
+    local cargo="cargo --locked"
+
+    # All the provided features including $use
+    $cargo build --no-default-features --features="$use $features"
+    $cargo test --no-default-features --features="$use $features"
+
+    read -r -a array <<< "$features"
+    local len="${#array[@]}"
+
+    if (( len > 1 )); then
+        for ((i = 0 ; i < len ; i++ ));
+        do
+            $cargo build --features="$use ${array[i]}"
+            $cargo test --features="$use ${array[i]}"
+
+            if (( i < len - 1 )); then
+               for ((j = i + 1 ; j < len ; j++ ));
+               do
+                   $cargo build --features="$use ${array[i]} ${array[j]}"
+                   $cargo test --features="$use ${array[i]} ${array[j]}"
+               done
+            fi
+        done
+    fi
+}
+
+# Lint the workspace then the individual crate examples.
+do_lint() {
+    # Use the current (recent/minimal) lock file.
+    local cargo="cargo +nightly --locked"
+
+    $cargo clippy --workspace -- -D warnings
+
+    for example in $EXAMPLES; do
+	name=$(echo "$example" | cut -d ':' -f 1)
+	features=$(echo "$example" | cut -d ':' -f 2)
+	$cargo clippy --example "$name" --features="$features" -- -D warnings
+    done
+}
+
+# We should not have any duplicate dependencies. This catches mistakes made upgrading dependencies
+# in one crate and not in another (e.g. upgrade bitcoin_hashes in bitcoin but not in secp).
+do_dup_deps() {
+    duplicate_dependencies=$(
+        # Only show the actual duplicated deps, not their reverse tree, then
+        # whitelist the 'syn' crate which is duplicated but it's not our fault.
+        cargo tree  --target=all --all-features --duplicates \
+            | grep '^[0-9A-Za-z]' \
+            | grep -v 'syn' \
+            | wc -l
+                          )
+    if [ "$duplicate_dependencies" -ne 0 ]; then
+        echo "Dependency tree is broken, contains duplicates"
+        cargo tree  --target=all --all-features --duplicates
+        exit 1
+    fi
+}
+
+# Build the docs with a nightly toolchain, in unison with the function
+# below this checks that we feature guarded docs imports correctly.
+build_docs_with_nightly_toolchain() {
+    local cargo="cargo +nightly --locked"
+
+    RUSTDOCFLAGS="--cfg docsrs -D warnings -D rustdoc::broken-intra-doc-links" $cargo doc --all-features
+}
+
+# Build the docs with a stable toolchain, in unison with the function
+# above this checks that we feature guarded docs imports correctly.
+build_docs_with_stable_toolchain() {
+    local cargo="cargo +stable --locked"
+
+    RUSTDOCFLAGS="-D warnings" $cargo doc --all-features
+}
+
+do_wasm() {
+    clang --version &&
+	CARGO_TARGET_DIR=wasm cargo install --force wasm-pack &&
+	printf '\n[target.wasm32-unknown-unknown.dev-dependencies]\nwasm-bindgen-test = "0.3"\n' >> Cargo.toml &&
+	printf '\n[lib]\ncrate-type = ["cdylib", "rlib"]\n' >> Cargo.toml &&
+	CC=clang-9 wasm-pack build &&
+	CC=clang-9 wasm-pack test --node;
+}
+
+do_asan() {
+    cargo clean
+    CC='clang -fsanitize=address -fno-omit-frame-pointer'                                        \
+      RUSTFLAGS='-Zsanitizer=address -Clinker=clang -Cforce-frame-pointers=yes'                    \
+      ASAN_OPTIONS='detect_leaks=1 detect_invalid_pointer_pairs=1 detect_stack_use_after_return=1' \
+      cargo test --lib --no-default-features --features="$ASAN_FEATURES" -Zbuild-std --target x86_64-unknown-linux-gnu
+    cargo clean
+    CC='clang -fsanitize=memory -fno-omit-frame-pointer'                                         \
+      RUSTFLAGS='-Zsanitizer=memory -Zsanitizer-memory-track-origins -Cforce-frame-pointers=yes'   \
+      cargo test --lib --no-default-features --features="$ASAN_FEATURES" -Zbuild-std --target x86_64-unknown-linux-gnu
+}
+
+# Bench only works with a non-stable toolchain (nightly, beta).
+do_bench() {
+    RUSTFLAGS='--cfg=bench' cargo bench
+}
+
+# This is only relevant for hashes.
+do_schemars() {
+    cd "extended_tests/schemars" > /dev/null
+    cargo test
+}
+
+#
+# Main script
+#
+main "$@"
+exit 0
diff --git a/contrib/test_vars.sh b/contrib/test_vars.sh
new file mode 100644
index 00000000..3f96f89e
--- /dev/null
+++ b/contrib/test_vars.sh
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+CRATES="`cargo metadata --no-deps --format-version 1 | jq -j -r '.packages | map(.manifest_path | rtrimstr("/Cargo.toml") | ltrimstr("'$PWD'/")) | join(" ")'`"
+DEPS="recent minimal"
diff --git a/hashes/contrib/extra_tests.sh b/hashes/contrib/extra_tests.sh
new file mode 100755
index 00000000..aa688517
--- /dev/null
+++ b/hashes/contrib/extra_tests.sh
@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+set -ex
+
+REPO_DIR=$(git rev-parse --show-toplevel)
+
+if [ "$DO_SCHEMARS_TESTS" = true ]; then
+    pushd "$REPO_DIR/hashes/extended_tests/schemars" > /dev/null
+    cargo test
+    popd > /dev/null
+fi
diff --git a/hashes/contrib/test.sh b/hashes/contrib/test.sh
deleted file mode 100755
index 72ee47ce..00000000
--- a/hashes/contrib/test.sh
+++ /dev/null
@@ -1,124 +0,0 @@
-#!/usr/bin/env bash
-
-set -ex
-
-FEATURES="serde std io alloc"
-
-cargo --version
-rustc --version
-
-# Work out if we are using a nightly toolchain.
-NIGHTLY=false
-if cargo --version | grep nightly >/dev/null; then
-    NIGHTLY=true
-fi
-
-# Pin dependencies as required if we are using MSRV toolchain.
-if cargo --version | grep "1\.48"; then
-    # 1.0.157 uses syn 2.0 which requires edition 2021
-    cargo update -p serde_json --precise 1.0.99
-    cargo update -p serde --precise 1.0.156
-fi
-
-# Make all cargo invocations verbose
-export CARGO_TERM_VERBOSE=true
-
-# Defaults / sanity checks
-cargo build
-cargo test
-
-if [ "$DO_LINT" = true ]
-then
-    cargo clippy --locked --all-features --all-targets -- -D warnings
-fi
-
-if [ "$DO_FEATURE_MATRIX" = true ]; then
-    cargo build --locked --no-default-features
-    cargo test --locked --no-default-features
-
-    # All features
-    cargo build --locked --no-default-features --features="$FEATURES"
-    cargo test --locked --no-default-features --features="$FEATURES"
-    # Single features
-    for feature in ${FEATURES}
-    do
-        cargo build --locked --no-default-features --features="$feature"
-        cargo test --locked --no-default-features --features="$feature"
-		# All combos of two features
-		for featuretwo in ${FEATURES}; do
-			cargo build --locked --no-default-features --features="$feature $featuretwo"
-			cargo test --locked --no-default-features --features="$feature $featuretwo"
-		done
-    done
-
-    # Other combos
-    cargo test --locked --no-default-features --features="std,schemars"
-fi
-
-REPO_DIR=$(git rev-parse --show-toplevel)
-
-if [ "$DO_SCHEMARS_TESTS" = true ]; then
-    pushd "$REPO_DIR/hashes/extended_tests/schemars" > /dev/null
-    cargo test
-    popd > /dev/null
-fi
-
-# Build the docs if told to (this only works with the nightly toolchain)
-if [ "$DO_DOCSRS" = true ]; then
-    RUSTDOCFLAGS="--cfg docsrs -D warnings -D rustdoc::broken-intra-doc-links" cargo +nightly doc --all-features
-fi
-
-# Build the docs with a stable toolchain, in unison with the DO_DOCSRS command
-# above this checks that we feature guarded docs imports correctly.
-if [ "$DO_DOCS" = true ]; then
-    RUSTDOCFLAGS="-D warnings" cargo +stable doc --all-features
-fi
-
-# Webassembly stuff
-if [ "$DO_WASM" = true ]; then
-    clang --version &&
-    CARGO_TARGET_DIR=wasm cargo install --force wasm-pack &&
-    printf '\n[target.wasm32-unknown-unknown.dev-dependencies]\nwasm-bindgen-test = "0.3"\n' >> Cargo.toml &&
-    printf '\n[lib]\ncrate-type = ["cdylib", "rlib"]\n' >> Cargo.toml &&
-    CC=clang-9 wasm-pack build &&
-    CC=clang-9 wasm-pack test --node;
-fi
-
-# Address Sanitizer
-if [ "$DO_ASAN" = true ]; then
-    cargo clean
-    CC='clang -fsanitize=address -fno-omit-frame-pointer'                                        \
-    RUSTFLAGS='-Zsanitizer=address -Clinker=clang -Cforce-frame-pointers=yes'                    \
-    ASAN_OPTIONS='detect_leaks=1 detect_invalid_pointer_pairs=1 detect_stack_use_after_return=1' \
-    cargo test --lib --no-default-features --features="$FEATURES" -Zbuild-std --target x86_64-unknown-linux-gnu
-    cargo clean
-    CC='clang -fsanitize=memory -fno-omit-frame-pointer'                                         \
-    RUSTFLAGS='-Zsanitizer=memory -Zsanitizer-memory-track-origins -Cforce-frame-pointers=yes'   \
-    cargo test --lib --no-default-features --features="$FEATURES" -Zbuild-std --target x86_64-unknown-linux-gnu
-fi
-
-# Run formatter if told to.
-if [ "$DO_FMT" = true ]; then
-    if [ "$NIGHTLY" = false ]; then
-        echo "DO_FMT requires a nightly toolchain (consider using RUSTUP_TOOLCHAIN)"
-        exit 1
-    fi
-    rustup component add rustfmt
-    cargo fmt --check
-fi
-
-# Bench if told to, only works with non-stable toolchain (nightly, beta).
-if [ "$DO_BENCH" = true ]
-then
-    if [ "$NIGHTLY" = false ]
-    then
-        if [ -n "$RUSTUP_TOOLCHAIN" ]
-        then
-            echo "RUSTUP_TOOLCHAIN is set to a non-nightly toolchain but DO_BENCH requires a nightly toolchain"
-        else
-            echo "DO_BENCH requires a nightly toolchain"
-        fi
-        exit 1
-    fi
-    RUSTFLAGS='--cfg=bench' cargo bench
-fi
diff --git a/hashes/contrib/test_vars.sh b/hashes/contrib/test_vars.sh
new file mode 100644
index 00000000..a75854cd
--- /dev/null
+++ b/hashes/contrib/test_vars.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+# Test all these features with "std" enabled.
+FEATURES_WITH_STD="io serde small-hash schemars"
+
+# Test all these features without "std" enabled.
+FEATURES_WITHOUT_STD="alloc serde small-hash"
+
+# Run address sanitizer with these features.
+ASAN_FEATURES="std io serde"
+
+# Run and lint these examples.
+EXAMPLES=""
diff --git a/hashes/embedded/scripts/env.sh b/hashes/embedded/scripts/env.sh
index 125162b6..7ea1e31c 100644
--- a/hashes/embedded/scripts/env.sh
+++ b/hashes/embedded/scripts/env.sh
@@ -1,2 +1,4 @@
+#!/usr/bin/env bash
+
 export RUSTFLAGS="-C link-arg=-Tlink.x"
 export CARGO_TARGET_THUMBV7M_NONE_EABI_RUNNER="qemu-system-arm -cpu cortex-m3 -machine mps2-an385 -nographic -semihosting-config enable=on,target=native -kernel"
diff --git a/internals/contrib/test_vars.sh b/internals/contrib/test_vars.sh
new file mode 100644
index 00000000..22b5b7e3
--- /dev/null
+++ b/internals/contrib/test_vars.sh
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+# Test all these features with "std" enabled.
+FEATURES_WITH_STD="serde"
+
+# Test all these features without "std" enabled.
+FEATURES_WITHOUT_STD="alloc serde"
+
+# Run and lint these examples.
+EXAMPLES=""
diff --git a/io/contrib/test_vars.sh b/io/contrib/test_vars.sh
new file mode 100644
index 00000000..9eac7dcc
--- /dev/null
+++ b/io/contrib/test_vars.sh
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+# Test all these features with "std" enabled.
+FEATURES_WITH_STD=""
+
+# Test all these features without "std" enabled.
+FEATURES_WITHOUT_STD="alloc"
+
+# Run and lint these examples.
+EXAMPLES=""
diff --git a/units/contrib/test.sh b/units/contrib/test.sh
deleted file mode 100755
index e23decf7..00000000
--- a/units/contrib/test.sh
+++ /dev/null
@@ -1,79 +0,0 @@
-#!/usr/bin/env bash
-
-set -ex
-
-FEATURES="std alloc serde"
-
-cargo --version
-rustc --version
-
-# Work out if we are using a nightly toolchain.
-NIGHTLY=false
-if cargo --version | grep nightly >/dev/null; then
-    NIGHTLY=true
-fi
-
-# Make all cargo invocations verbose
-export CARGO_TERM_VERBOSE=true
-
-# Defaults / sanity checks
-cargo build
-cargo test
-
-if [ "$DO_LINT" = true ]
-then
-    cargo clippy --locked --all-features --all-targets -- -D warnings
-fi
-
-if [ "$DO_FEATURE_MATRIX" = true ]; then
-    # No features
-    cargo build --locked --no-default-features
-    cargo test --locked --no-default-features
-
-    # Default features (this is std and alloc)
-    cargo build --locked
-    cargo test --locked
-
-    # All features
-    cargo build --locked --no-default-features --all-features
-    cargo test --locked --no-default-features --all-features
-fi
-
-REPO_DIR=$(git rev-parse --show-toplevel)
-
-# Build the docs if told to (this only works with the nightly toolchain)
-if [ "$DO_DOCSRS" = true ]; then
-    RUSTDOCFLAGS="--cfg docsrs -D warnings -D rustdoc::broken-intra-doc-links" cargo +nightly doc --all-features
-fi
-
-# Build the docs with a stable toolchain, in unison with the DO_DOCSRS command
-# above this checks that we feature guarded docs imports correctly.
-if [ "$DO_DOCS" = true ]; then
-    RUSTDOCFLAGS="-D warnings" cargo +stable doc --all-features
-fi
-
-# Run formatter if told to.
-if [ "$DO_FMT" = true ]; then
-    if [ "$NIGHTLY" = false ]; then
-        echo "DO_FMT requires a nightly toolchain (consider using RUSTUP_TOOLCHAIN)"
-        exit 1
-    fi
-    rustup component add rustfmt
-    cargo fmt --check
-fi
-
-# Bench if told to, only works with non-stable toolchain (nightly, beta).
-if [ "$DO_BENCH" = true ]
-then
-    if [ "$NIGHTLY" = false ]
-    then
-        if [ -n "$RUSTUP_TOOLCHAIN" ]
-        then
-            echo "RUSTUP_TOOLCHAIN is set to a non-nightly toolchain but DO_BENCH requires a nightly toolchain"
-        else
-            echo "DO_BENCH requires a nightly toolchain"
-        fi
-        exit 1
-    fi
-    RUSTFLAGS='--cfg=bench' cargo bench
-fi
diff --git a/units/contrib/test_vars.sh b/units/contrib/test_vars.sh
new file mode 100644
index 00000000..22b5b7e3
--- /dev/null
+++ b/units/contrib/test_vars.sh
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+# Test all these features with "std" enabled.
+FEATURES_WITH_STD="serde"
+
+# Test all these features without "std" enabled.
+FEATURES_WITHOUT_STD="alloc serde"
+
+# Run and lint these examples.
+EXAMPLES=""