[M8] reusable libraries: install layout + cargoxx-path deps

tests/e2e/buildCppPackage/src/bin/extra.cpp

@@ -0,0 +1,8 @@
+#include <nlohmann/json.hpp>
+import std;
+int main() {
+    nlohmann::json j;
+    j["from"] = "extra";
+    std::println("{}", j["from"].get<std::string>());
+    return 0;
+}

tests/e2e/pathDep/Cargoxx.toml

@@ -0,0 +1,7 @@
+[package]
+name = "consumer"
+version = "0.1.0"
+edition = "cpp23"
+
+[dependencies]
+greeter = { path = "./greeter" }

tests/e2e/pathDep/flake.nix

@@ -0,0 +1,10 @@
+{
+  description = "e2e cargoxx path-dep smoke";
+
+  inputs.cargoxx.url = "path:../../..";
+
+  outputs = { self, cargoxx }: {
+    packages.x86_64-linux.default =
+      cargoxx.lib.x86_64-linux.buildCppPackage { src = ./.; };
+  };
+}

tests/e2e/pathDep/greeter/Cargoxx.toml

@@ -0,0 +1,4 @@
+[package]
+name = "greeter"
+version = "0.1.0"
+edition = "cpp23"

tests/e2e/pathDep/greeter/src/lib.cppm

@@ -0,0 +1,8 @@
+export module greeter;
+import std;
+
+export namespace greeter {
+auto hello(std::string_view who) -> std::string {
+    return std::format("Hello from greeter, {}!", who);
+}
+} // namespace greeter

tests/e2e/pathDep/run.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+repo="$(cd "${here}/../../.." && pwd)"
+cargoxx_bin="${CARGOXX_BIN:-${repo}/build/debug/cargoxx}"
+
+if [[ ! -x "${cargoxx_bin}" ]]; then
+    echo "error: cargoxx binary not found at ${cargoxx_bin}" >&2
+    echo "build it first: nix develop --command cmake --build build/debug" >&2
+    exit 1
+fi
+
+work="$(mktemp -d -t cargoxx-e2e-pathdep-XXXXXX)"
+trap 'rm -rf "${work}"' EXIT
+
+cp -r "${here}/." "${work}/"
+sed -i "s|path:\\.\\./\\.\\./\\.\\.|path:${repo}|" "${work}/flake.nix"
+
+cd "${work}"
+
+echo "=== cargoxx build --no-build in greeter (path dep generates its own lock)"
+(cd greeter && "${cargoxx_bin}" build --no-build)
+
+echo "=== cargoxx build --no-build in consumer"
+"${cargoxx_bin}" build --no-build
+
+[[ -f Cargoxx.lock ]] || { echo "Cargoxx.lock missing"; exit 1; }
+grep -q "source_kind = 'cargoxx-path'" Cargoxx.lock || \
+    { echo "Cargoxx.lock missing source_kind = cargoxx-path"; exit 1; }
+
+# nix build needs the source tree to be a git tree so 'path:' input copies
+# Cargoxx.lock into the store. Init a throwaway git here.
+git init -q
+git add -A
+git -c user.email=e2e@cargoxx -c user.name=e2e commit -q -m fixture
+
+echo "=== nix build .#default"
+out="$(nix build .#default --no-link --print-out-paths \
+    --extra-experimental-features 'nix-command flakes')"
+
+[[ -n "${out}" ]] || { echo "nix build produced no output path"; exit 1; }
+[[ -x "${out}/bin/consumer" ]] || { echo "missing ${out}/bin/consumer"; exit 1; }
+
+echo "=== execute"
+"${out}/bin/consumer"
+
+echo "ok"

tests/e2e/pathDep/src/main.cpp

@@ -0,0 +1,7 @@
+import std;
+import greeter;
+
+int main() {
+    std::println("{}", greeter::hello("world"));
+    return 0;
+}