remove bash -lc

npm_install.py

@@ -584,15 +584,33 @@ def install_node_and_yarn(node_pkg: str):
         os.symlink("/usr/bin/yarnpkg","/usr/bin/yarn")
 
 def _build_frontend(src_frontend: Path, dest_frontend: Path):
+    def _which(cmd: str) -> bool:
+        import shutil as _s
+        return _s.which(cmd) is not None
+
+    yarn = "yarn" if _which("yarn") else ("yarnpkg" if _which("yarnpkg") else "")
+    if not yarn:
+        run(["corepack", "enable"], check=False)
+        run(["corepack", "prepare", "yarn@stable", "--activate"], check=False)
+        yarn = "yarn" if _which("yarn") else ("yarnpkg" if _which("yarnpkg") else "")
+    if not yarn:
+        raise RuntimeError("Brak Yarn. Zainstaluj: npm i -g yarn  (lub użyj corepack).")
+
     with step("Installing frontend dependencies (yarn)"):
         os.environ["NODE_ENV"] = "development"
         os.chdir(src_frontend)
-        run(["yarn", "cache", "clean", "--all"])
-        run(["yarn", "install"])
+        cache_dir = (run_out([yarn, "cache", "dir"], check=False) or "").strip()
+        if cache_dir and not Path(cache_dir).exists():
+            Path(cache_dir).mkdir(parents=True, exist_ok=True)
+        run([yarn, "cache", "clean"], check=False)
+
+        run([yarn, "install"])
+
     with step("Building frontend (yarn build)"):
         env = os.environ.copy()
         env["NODE_OPTIONS"] = "--openssl-legacy-provider"
-        run(["yarn", "build"], env=env)
+        run([yarn, "build"], env=env)
+
     with step("Copying frontend artifacts"):
         shutil.copytree(src_frontend / "dist", dest_frontend, dirs_exist_ok=True)
         if (src_frontend / "app-images").exists():