abroot pkg apply fails with "device or resource busy" on Vanilla OS 2.0 Orchid (ABRoot 2.5.0)

System:

• Vanilla OS 2.0 Orchid
• ABRoot version: 2.5.0

Problem:

Running:

pkexec abroot pkg apply

always fails at the end with:

ERROR Apply command failed: device or resource busy

The package build appears to complete successfully, but the final apply step fails.

Verbose output ends with:

Partition.Unmount: successfully unmounted /part-future
Partition.Unmount: device or resource busy
Partition.Mount: device or resource busy
ABSystem.RunOperation: device or resource busy
ERROR Apply command failed: device or resource busy

Additional information:

findmnt shows:

/part-future -> /dev/mapper/vos--root-root--b

mount | grep part-future

returns:

/dev/mapper/vos--root-root--b on /part-future type btrfs (...)

Running:

fuser -vm /part-future

returns only:

root kernel mount /part-future

There are no user processes holding the mount.

Because of this failure, packages remain unstaged and cannot be applied to the future slot.

Is this a known issue with ABRoot 2.5.0 or is there a workaround?

Start by reproducing pkexec abroot pkg apply on Vanilla OS 2.0 Orchid with ABRoot 2.5.0 and inspect the verbose unmount and mount failures for /part-future. Use findmnt, mount, and fuser as reported to determine why the future slot remains busy. Done means the apply operation completes and packages are staged in the future slot.