fix install again

install.sh

@@ -26,7 +26,9 @@ if [[ ! "$checksum" =~ ^[a-fA-F0-9]{64}$ ]]; then
     printf 'Invalid release checksum\n' >&2
     exit 1
 fi
-if ! (cd "$install" && printf '%s  stanp-opencode.tgz\n' "$checksum" | sha256sum --check --status); then
+hash_output=$(sha256sum "$install/stanp-opencode.tgz")
+read -r actual _ <<< "$hash_output"
+if [[ ! "$actual" =~ ^[a-fA-F0-9]{64}$ || "$actual" != "$checksum" ]]; then
     printf 'Release checksum mismatch; installation unchanged\n' >&2
     exit 1
 fi

tests/install.test.ts

@@ -145,10 +145,22 @@ if [[ -n "$output" ]]; then
 else
     cat "$FIXTURE_DIR/$source"
 fi
+`,
+        ),
+        writeFile(
+            join(bin, "sha256sum"),
+            `#!/usr/bin/env bash
+if [[ "\${1:-}" == -* ]]; then
+    printf 'usage: sha256sum [-bctwz] [files ...]\n' >&2
+    exit 1
+fi
+PATH="\${PATH#*:}"
+export PATH
+exec sha256sum "$@"
 `,
         ),
     ]);
-    await chmod(join(bin, "curl"), 0o755);
+    await Promise.all([chmod(join(bin, "curl"), 0o755), chmod(join(bin, "sha256sum"), 0o755)]);
     const result = await run(["bash", installer], directory, env);
     return { directory, config, env, result };
 }