fix(ubicloud): pack takes an ignored subdirectory whole; correct the cmd_run tree-check comment

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

scripts/ubicloud/ubi-runner.sh

@@ -1116,11 +1116,14 @@ cmd_down() {
 # subdirectory of a work tree ships the same file set without a .git: git's
 # local transport fetches only from a repository's root, and the whole
 # repository's .git would show the VM every file outside the subdirectory as
-# deleted (GST-935).
+# deleted (GST-935). A directory git ignores has no such file set and is
+# taken whole, like a non-git directory.
 cmd_pack() {
   local src tmp gitdir branch head entry
   src=$(cd "${1:-.}" && pwd)
-  if git -C "$src" rev-parse --is-inside-work-tree >/dev/null 2>&1 && [ -n "$(git -C "$src" rev-parse --show-prefix)" ]; then
+  if ! git -C "$src" rev-parse --is-inside-work-tree >/dev/null 2>&1 || git -C "$src" check-ignore -q .; then
+    COPYFILE_DISABLE=1 tar -C "$src" -czf - .
+  elif [ -n "$(git -C "$src" rev-parse --show-prefix)" ]; then
     (
       cd "$src"
       export COPYFILE_DISABLE=1
@@ -1131,7 +1134,7 @@ cmd_pack() {
         | tar --null -T - -cf - \
         | gzip -c
     )
-  elif git -C "$src" rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+  else
     head=$(git -C "$src" rev-parse --verify -q HEAD) || die "pack: $src has no commits; the VM needs a HEAD to fingerprint"
     branch=$(git -C "$src" symbolic-ref -q --short HEAD || true)
     tmp=$(mktemp -d)
@@ -1182,8 +1185,6 @@ cmd_pack() {
         && gzip -c "$tmp/files.tar"
     )
     rm -rf "$tmp"; trap - EXIT
-  else
-    COPYFILE_DISABLE=1 tar -C "$src" -czf - .
   fi
 }
 
@@ -1408,8 +1409,10 @@ cmd_run() {
       for n in ${passes[@]+"${passes[@]}"}; do printf 'export %s=%q\n' "$n" "${!n}"; done; } \
       | remote "$name" 'umask 077 && cat > ~/.ubirun-env'
     cmd_sync "$name" "$src" "$dest"
-    # A subdirectory of a checkout uploads the whole .git with only its own
-    # files, so its tree is compared VM to VM (tiers) but not to this side.
+    # A subdirectory of a checkout ships without a .git, and its local tree
+    # (a scratch repository, blind to the parent's ignore rules) can count
+    # files pack leaves out, so it is compared VM to VM (tiers) but not to
+    # this side.
     if [ -z "$(git -C "$src" rev-parse --show-prefix 2>/dev/null)" ]; then
       vmt=$(vm_tree "$name" "$qdest") || vmt=unavailable
       if [ "$vmt" != "$TREE" ]; then

test/ubicloud-runner.test.ts

@@ -385,7 +385,7 @@ test('pack ships a linked worktree with a self-contained .git on the checked-out
     const d = mkdtempSync(join(tmpdir(), 'ubi-pack-subdir-'));
     try {
       const sh = (cmd: string, cwd: string) => { const r = Bun.spawnSync(['bash', '-c', cmd], { cwd, timeout: 30_000, env: { ...process.env, GIT_AUTHOR_NAME: 't', GIT_AUTHOR_EMAIL: 't@t', GIT_COMMITTER_NAME: 't', GIT_COMMITTER_EMAIL: 't@t' } }); expect(r.exitCode, `${cmd}\n${r.stderr.toString()}`).toBe(0); return r.stdout.toString(); };
-      sh('git init -q repo && cd repo && echo top > top && mkdir -p sub/nested && echo a > sub/a && echo b > sub/nested/b && echo g > sub/gone && echo "*.log" > sub/.gitignore && git add -A && git commit -qm one && git worktree add -q ../wt', d);
+      sh('git init -q repo && cd repo && echo top > top && echo ign/ > .gitignore && mkdir -p sub/nested ign && echo i > ign/i && echo a > sub/a && echo b > sub/nested/b && echo g > sub/gone && echo "*.log" > sub/.gitignore && git add -A && git commit -qm one && git worktree add -q ../wt', d);
       const tree = (dir: string) => sh('find . -type f | sort', dir).split('\n').filter(Boolean);
       for (const checkout of ['repo', 'wt']) {
         const sub = join(d, checkout, 'sub');
@@ -395,6 +395,9 @@ test('pack ships a linked worktree with a self-contained .git on the checked-out
         expect(tree(vm)).toEqual(['./.gitignore', './a', './nested/b', './new']);
         expect(readFileSync(join(vm, 'a'), 'utf8')).toBe('edited\n');
       }
+      // A directory git ignores lists no files, so it is taken whole instead of shipping an empty archive.
+      sh(`mkdir -p repo/ign/deep && echo d > repo/ign/deep/d && mkdir vm-ign && bash ${JSON.stringify(join(DIR, 'ubi-runner.sh'))} pack repo/ign | tar -xzf - -C vm-ign`, d);
+      expect(tree(join(d, 'vm-ign'))).toEqual(['./deep/d', './i']);
     } finally { rmSync(d, { recursive: true, force: true }); }
   }, 60_000);