Summary
On Windows, hermes update attempted to install managed uv into the Hermes bin directory and failed, even though uv was already installed and available on PATH.
The update continued using pip, so Hermes itself was eventually usable, but the managed uv step failed and may confuse users during update.
Environment
- OS: Windows 11
- Shell: PowerShell
- Hermes project path:
C:\Users\Srika\AppData\Local\hermes\hermes-agent
- Python: 3.11.15
- Node.js: v24.15.0
- Existing uv install:
uv 0.11.14 (3fdfdc7d4 2026-05-12 x86_64-pc-windows-msvc)C:\Users\Srika\.local\bin\uv.exe
What happened
During hermes update, the updater printed:
→ Updating Python dependencies...
→ Installing managed uv into C:\Users\Srika\AppData\Local\hermes\bin ...
✗ Failed to install managed uv: Command '['powershell', '-ExecutionPolicy', 'Bypass', '-c', 'irm https://astral.sh/uv/install.ps1 | iex']' returned non-zero exit status 1.
However, uv was already installed and working:
uv --version
where.exe uv
Output:
uv 0.11.14 (3fdfdc7d4 2026-05-12 x86_64-pc-windows-msvc)
C:\Users\Srika\.local\bin\uv.exe
The Hermes bin folder existed:
Test-Path "$env:LOCALAPPDATA\hermes\bin"
Output:
But the managed uv.exe was missing there:
Test-Path "$env:LOCALAPPDATA\hermes\bin\uv.exe"
Output:
Workaround used
Copied the already-working uv.exe into the Hermes managed bin path:
Copy-Item "$env:USERPROFILE\.local\bin\uv.exe" "$env:LOCALAPPDATA\hermes\bin\uv.exe" -Force
Verified:
& "$env:LOCALAPPDATA\hermes\bin\uv.exe" --version
Output:
uv 0.11.14 (3fdfdc7d4 2026-05-12 x86_64-pc-windows-msvc)
After putting Hermes bin first in PATH for the session:
Output:
C:\Users\Srika\AppData\Local\hermes\bin\uv.exe
C:\Users\Srika\.local\bin\uv.exe
Expected behavior
If uv is already available on PATH, hermes update should either:
- Use the existing
uv, or
- Copy/link it into the Hermes managed bin path, or
- Provide a clearer recovery message if the managed install script fails.
Actual behavior
Hermes tried to run the uv PowerShell installer, failed with a non-zero exit status, and did not fall back to the existing working uv.exe on PATH.
Why this matters
For Windows users, this looks like a serious update failure even though the system already has a valid uv installation. A fallback to existing PATH uv, or a clearer message, would make the update process much smoother.
Summary
On Windows,
hermes updateattempted to install manageduvinto the Hermes bin directory and failed, even thoughuvwas already installed and available on PATH.The update continued using
pip, so Hermes itself was eventually usable, but the manageduvstep failed and may confuse users during update.Environment
C:\Users\Srika\AppData\Local\hermes\hermes-agentuv 0.11.14 (3fdfdc7d4 2026-05-12 x86_64-pc-windows-msvc)C:\Users\Srika\.local\bin\uv.exeWhat happened
During
hermes update, the updater printed:However,
uvwas already installed and working:Output:
The Hermes bin folder existed:
Output:
But the managed
uv.exewas missing there:Output:
Workaround used
Copied the already-working
uv.exeinto the Hermes managed bin path:Verified:
Output:
After putting Hermes bin first in PATH for the session:
where.exe uvOutput:
Expected behavior
If
uvis already available on PATH,hermes updateshould either:uv, orActual behavior
Hermes tried to run the
uvPowerShell installer, failed with a non-zero exit status, and did not fall back to the existing workinguv.exeon PATH.Why this matters
For Windows users, this looks like a serious update failure even though the system already has a valid
uvinstallation. A fallback to existing PATHuv, or a clearer message, would make the update process much smoother.