Flamenco-Management/FLAMENCO_BUG_REPORT.md

System Information Operating System(s): Win11 25h2

Flamenco Version Is Broken: 3.8 Worked OK: unknown

When Flamenco is ran from a Windows machine, with the shared-storage set to an SMB share, the symlinks created by Shaman appear to be either completely useless at worst, context dependent at best.

1. Download and configure Flamenco
2. Configure the security policy as instructed in the documentation
3. Set shaman: enabled: true.
4. Set shared_storage_path. I was originally hosting the files on a TrueNAS SMB share (mapped to F:). Testing it with a local drive (T:\Flamenco) results with the intended behavior.
5. Submit job

The symlinks created within jobs will not be universally accessible by Windows. All Windows workers (I have only tested Windows) will fail:

2026-01-08T15:51:58-07:00 Task assigned to worker i9kf (3690a968-f7ee-49d5-adb7-76154761d435)
2026-01-08T15:51:58-07:00 task changed status queued -> active
going to run:

    'F:\software\Blender\blender.exe' -b -y --gpu-backend opengl 'F:\jobs/SSD_2B/SSD_2B.flamenco.blend' --python-expr '
import bpy

cycles_prefs = bpy.context.preferences.addons['"'"'cycles'"'"'].preferences
cycles_prefs.compute_device_type = '"'"'OPTIX'"'"'
for dev in cycles_prefs.get_devices_for_type('"'"'OPTIX'"'"'):
    dev.use = (dev.type != '"'"'CPU'"'"')
' --python-expr 'import bpy; bpy.context.scene.cycles.device = '"'"'GPU'"'"'' --render-output 'F:/renders/SSD_2B/2026-01-08_151057/######' --render-format PNG --render-frame 0..15

pid=32124 > 00:10.047  reports          | ERROR File format is not supported in file "F:\jobs\SSD_2B\SSD_2B.flamenco.blend"
pid=32124 > Blender 5.0.1 (hash a3db93c5b259 built 2025-12-16 01:32:30)
pid=32124 > Cannot read ARP prefs
pid=32124 > Update armature presets...
pid=32124 > animation_layers_updater addon: Verbose is enabled
pid=32124 > animation_layers_updater addon: Read in JSON settings from file
pid=32124 > 
pid=32124 > Blender quit
Failed: command exited abnormally with code 1
2026-01-08T15:52:11-07:00 Task failed by 1 worker, Manager will mark it as soft failure. 2 more failures will cause hard failure.
2026-01-08T15:52:11-07:00 task changed status active -> soft-failed

Examining the jobfiles reveals the issue. The file is detected as .symlink type. However, the symlink points to the proper Shaman Blob.

If you right click and edit the symlink in notepad, it opens the blob: A proper blendfile with gzip compression.

When opened in VSCode, it opens blank.

When copied to another folder, it copies a blank file.

If you open the symlink in blender, the error is replicated: File format is not supported in file "F:\jobs\SSD_2B\SSD_2B.flamenco.blend"

Opening the actual blob in blender works, but obviously it's still pointing to files that cannot be found from the blob's directory. I only did this to verify that the blobs were written correctly, and they clearly are.

18:03.360  blend            | Read blend: "F:\file-store\stored\14\0c6efa48408ce1ee0a7296e057e798b1a162d7bc60d542b03d8938f33776c8\1253809.blob"
18:03.391  blend.readfile   | Read library: 'F:\file-store\stored\14\0c6efa48408ce1ee0a7296e057e798b1a162d7bc60d542b03d8938f33776c8\_outside_project\A\1 Amazon_Active_Projects\1 BlenderAssets\Amazon\Scenes\LivingRoom_v2.blend', '//_outside_project/A/1 Amazon_Active_Projects/1 BlenderAssets/Amazon/Scenes/LivingRoom_v2.blend', parent '<direct>'
18:03.391  blend.readfile   | Cannot find lib 'F:\file-store\stored\14\0c6efa48408ce1ee0a7296e057e798b1a162d7bc60d542b03d8938f33776c8\_outside_project\A\1 Amazon_Active_Projects\1 BlenderAssets\Amazon\Scenes\LivingRoom_v2.blend'
18:03.391  blend.readfile   | Read library: 'F:\file-store\stored\14\0c6efa48408ce1ee0a7296e057e798b1a162d7bc60d542b03d8938f33776c8\_outside_project\A\1 Amazon_Active_Projects\1 BlenderAssets\Amazon\Char\Customers\Mom.blend', '//_outside_project/A/1 Amazon_Active_Projects/1 BlenderAssets/Amazon/Char/Customers/Mom.blend', parent '<direct>'
18:03.391  blend.readfile   | Cannot find lib 'F:\file-store\stored\14\0c6efa48408ce1ee0a7296e057e798b1a162d7bc60d542b03d8938f33776c8\_outside_project\A\1 Amazon_Active_Projects\1 BlenderAssets\Amazon\Char\Customers\Mom.blend'
18:03.422  blend.readfile   | LIB: Collection: 'Living Room' missing from 'F:\file-store\stored\14\0c6efa48408ce1ee0a7296e057e798b1a162d7bc60d542b03d8938f33776c8\_outside_project\A\1 Amazon_Active_Projects\1 BlenderAssets\Amazon\Scenes\LivingRoom_v2.blend', parent '<direct>'
18:03.422

Root Cause

Windows creates Windows reparse points (not Unix symlinks) when creating symlinks on SMB shares. The behavior differs based on how the file is accessed:

1. Windows reparse points on SMB shares:

   • Windows stores the target path in reparse point metadata
   • Samba stores these as empty regular files on the server (doesn't understand Windows reparse points)
   • The target path is correctly stored and can be read via Get-Item .Target property

2. Why some applications work:

   • Windows Explorer/Notepad: Use file system filters that detect reparse points and automatically resolve them client-side by reading the Target property and opening the target file
   • This works because resolution happens on the Windows client, not the SMB server

3. Why Blender/other applications fail:

   • Blender/VSCode/programmatic I/O: Use direct file I/O operations (ReadAllBytes(), FileStream, etc.)
   • These operations don't use reparse point filters
   • SMB client doesn't automatically follow reparse points
   • Returns the empty file from the server (0 bytes)

Workarounds

1. Use local storage: Set shared_storage_path to a local NTFS drive (symlinks work perfectly)
2. Run Flamenco Manager on Linux/WSL: Use mfsymlinks mount option for SMB shares
3. Disable Shaman.