AgentFixboard
Fixed (verified)Last checked Hermes Agent#setup#regression

Windows in-app update deadlocks because the official Setup.exe predates HANDOFF_PID

The Desktop Update flow on Windows exits 2 and prints Hermes is still running. Close all Hermes windows and try the update again. A leftover marker then blocks later attempts with Another Hermes update is already running.

From GitHub

NousResearch/hermes-agent

IssuePull request

Difficulty
Easy
Time
~5 min
Steps
2
Fixed in
v2026.8.27
Last checked

Verified fix: PR #95069 merged on . Fixed in v2026.8.27 (first published release whose tag contains the merge commit). Last checked .

Symptom

The Desktop Update flow on Windows exits 2 and prints Hermes is still running. Close all Hermes windows and try the update again. A leftover marker then blocks later attempts with Another Hermes update is already running.

Evidence what you'll see

  • The downloaded Hermes-Setup.exe (?build=cc4cab2f592e, labeled v0.19.1) embeds commit ac68faa20c58 and does not contain the string HERMES_UPDATE_HANDOFF_PID. Tag v0.19.1 is cc4cab2f5 and does contain that string in apps/bootstrap-installer/src-tauri/src/update.rs.
  • The stale updater starts, self-adopts the marker, spawns hermes update, and does not set HERMES_UPDATE_HANDOFF_PID, so the child reads the marker as a foreign update and exits 2.
  • Running hermes update from a checkout that has the handoff, with the marker and HERMES_UPDATE_HANDOFF_PID set, succeeds.

Why it happens

The official Windows installer was built from a commit before 8c76fe19f, which is the change that lets the GUI updater's hermes update child pass the lock it already holds. Exit 2 is skipped by the generic retry, so the update that would ship the handoff never runs. Pull request 95069 heals a self-owned marker after that exit 2, drops the claim, and retries the child once.

Affected versions

Windows 11 (10.0.26200) x64, Hermes desktop v0.19.1 (2026.7.30), installer downloaded 2026-07-31 from the official download page. The failure reproduced after replacing the exe with a fresh download of the same stale binary.

Fix steps

0 of 2 done

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How to check it worked

  • The Desktop Update flow on Windows finishes without exit 2 and without Another Hermes update is already running.

If it still fails

  • Tag v2026.8.19 does not contain pull request 95069. Stay on v2026.8.27 or later.
  • A marker owned by a different live process is still refused. The pull request says only a self-owned marker plus exit 2 is healed.

Sources and credit

Summarized in our own words from these public reports. Credit goes to their authors.

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