## Thinking Path
> - Paperclip is the open source app people use to manage AI agents for
work
> - Agents can run in remote/sandboxed environments via the shared
sandbox managed-runtime in `@paperclipai/adapter-utils` (used by
SSH/E2B/Daytona and other sandbox providers), which syncs the workspace
into the sandbox by tarring it up and extracting it inside the pod/host
> - When the sandbox runs the harness as a non-root user whose
home/workspace dir it does not own (for example a hardened, non-root,
gVisor pod with an `emptyDir`-mounted workspace), the workspace upload
aborts before the agent can start
> - Root cause: `createTarballFromDirectory` archives `.`, embedding a
`./` self-entry whose mode/mtime tar then tries to restore onto the
**extraction target directory**; `chmod`/`utime` of `.` fails with
`Operation not permitted` for a non-owner
> - This is not specific to any one deployment: the `.` self-entry EPERM
can bite every sandbox provider built on the shared managed runtime as
soon as the extracting user does not own the target directory, which is
the norm for hardened non-root sandboxes
> - This pull request archives the directory's top-level entries by name
instead of `.`, so there is no `./` self-entry and extraction never
touches the target dir's metadata
> - The benefit is that workspace sync works in any sandbox where the
target dir is non-root or not owned by the extracting user, without
GNU-only tar flags
## Linked Issues or Issue Description
No existing issue; describing in-PR (bug).
- **What happens:** managed sandbox runs that sync the workspace fail at
upload with `tar: .: Cannot utime: Operation not permitted` / `tar: .:
Cannot change mode to ... : Operation not permitted`, aborting the run
before the harness starts.
- **Where:** `packages/adapter-utils/src/sandbox-managed-runtime.ts`, in
`createTarballFromDirectory` (archives `.`).
- **When:** the extraction target directory is not owned by the
(non-root) user extracting the tar inside the sandbox.
- Closely related (different root cause): #6560 (E2B workspace upload +
lease idle failures).
## What Changed
- `createTarballFromDirectory` enumerates the directory's top-level
entries with `fs.readdir` and passes them by name after `--` (guards
flag-like filenames) instead of archiving `.`, eliminating the `./`
self-entry that triggers the EPERM.
- Empty workspaces (legitimate for blank-workspace runs) write a valid
1024-byte all-zero EOF tar instead of invoking `tar` with no paths.
- `--exclude` patterns continue to apply (to nested matches and any
named entry).
## Verification
- `pnpm --filter @paperclipai/adapter-utils build` (tsc clean)
- `pnpm exec vitest run
packages/adapter-utils/src/sandbox-managed-runtime.test.ts` runs green
- New tests: uploaded workspace/asset tarballs contain no `.`/`./`
member yet still extract correctly; empty workspace produces a valid
(no-op) tarball. Existing managed-runtime sync test unchanged.
- Manually verified in a hardened (non-root, gVisor) sandbox pod: with
the fix, the workspace upload that previously aborted with the EPERM now
succeeds. That deployment is the reproduction and verification
environment; the fix itself is provider-agnostic.
## Risks
Low. Behavior is unchanged for owned/root targets; the archive contents
are the same minus the `./` self-entry (which tar recreates implicitly
on extract). Portable across GNU/BSD/busybox tar (no GNU-only
`--no-overwrite-dir`). No API/migration/UI impact.
## Model Used
Claude Opus 4.8 (`claude-opus-4-8`, 1M context), extended thinking +
tool use, via Claude Code.
## Checklist
- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work (bug fix in shared sandbox utils, not core feature
work)
- [x] I have searched GitHub for duplicate or related PRs and linked
them above (#6560)
- [x] I have either (a) linked existing issues OR (b) described the
issue in-PR following the relevant issue template
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [ ] If this change affects the UI, I have included before/after
screenshots (n/a, no UI)
- [ ] I have updated relevant documentation to reflect my changes (n/a,
internal behavior, no docs reference this)
- [x] I have considered and documented any risks above
- [x] All Paperclip CI gates are green
- [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
(the only finding was the description-template P2, resolved by this
description; the latest review covers the current head with no code
findings and all CI gates are green)
- [x] I will address all Greptile and reviewer comments before
requesting merge
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Jannes Stubbemann
93cdc5c1ce