Bug 1961739

Reproduced also on RHEL-8.4 with the following partitioning in the kickstart file:

bootloader --location=mbr
zerombr
clearpart --all --initlabel
autopart

Also reproducible on RHEL-9, bug 1961944.

upstream PR: https://github.com/storaged-project/blivet/pull/958

updates image for 8.5: http://file.emea.redhat.com/~vtrefny/img/rhbz1961739.img

Tested using compose RHEL-8.5.0-20210626.d.0 (python3-blivet-3.4.0-1.el8) and problem is still occurring.
In graphical installation, once storage configuration starts, a window pops up saying "An error occurred while activating your storage configuration" "device path does not exist or is not writable". 

from storage.log:

INFO:blivet:executing action: [226] destroy format xfs filesystem on lvmsnapshot vg_test-snap (id 85)
INFO:program:Running... udevadm settle --timeout=300
DEBUG:program:Return code: 0
DEBUG:testdata:sysfs attr /sys/class/block/sr0/device/model: 51454d55204456442d524f4d202020200a
DEBUG:blivet:               XFS.destroy: device: /dev/mapper/vg_test-snap ; type: xfs ; status: False ;
INFO:program:Running... udevadm settle --timeout=300
DEBUG:program:Return code: 0
DEBUG:testdata:sysfs attr /sys/class/block/sr0/device/model: 51454d55204456442d524f4d202020200a
ERROR:anaconda.modules.storage.installation:Failed to activate filesystems: device path does not exist or is not writable
INFO:anaconda.threading:Thread Failed: AnaTaskThread-ActivateFilesystemsTask-1 (139880334898944)
ERROR:anaconda.modules.common.task.task:Thread AnaTaskThread-ActivateFilesystemsTask-1 has failed: Traceback (most recent call last):
  File "/usr/lib64/python3.6/site-packages/pyanaconda/threading.py", line 280, in run
    threading.Thread.run(self)
  File "/usr/lib64/python3.6/threading.py", line 864, in run
    self._target(*self._args, **self._kwargs)
  File "/usr/lib64/python3.6/site-packages/pyanaconda/modules/common/task/task.py", line 97, in _task_run_callback
    self._set_result(self.run())
  File "/usr/lib64/python3.6/site-packages/pyanaconda/modules/storage/installation.py", line 94, in run
    raise StorageInstallationError(str(e)) from None
pyanaconda.modules.common.errors.installation.StorageInstallationError: device path does not exist or is not writable

INFO:anaconda.threading:Thread Done: AnaTaskThread-ActivateFilesystemsTask-1 (139880334898944)
WARNING:dasbus.server.handler:The call org.fedoraproject.Anaconda.Task.Finish has failed with an exception:
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/dasbus/server/handler.py", line 421, in _method_callback
    *unwrap_variant(parameters)
  File "/usr/lib/python3.6/site-packages/dasbus/server/handler.py", line 234, in _handle_call
    return handler(*parameters)
  File "/usr/lib64/python3.6/site-packages/pyanaconda/modules/common/task/task_interface.py", line 114, in Finish
    self.implementation.finish()
  File "/usr/lib64/python3.6/site-packages/pyanaconda/modules/common/task/task.py", line 161, in finish
    threadMgr.raise_if_error(self._thread_name)
  File "/usr/lib64/python3.6/site-packages/pyanaconda/threading.py", line 171, in raise_if_error
    raise exc_info[0](exc_info[1]).with_traceback(exc_info[2])
  File "/usr/lib64/python3.6/site-packages/pyanaconda/threading.py", line 280, in run
    threading.Thread.run(self)
  File "/usr/lib64/python3.6/threading.py", line 864, in run
    self._target(*self._args, **self._kwargs)
  File "/usr/lib64/python3.6/site-packages/pyanaconda/modules/common/task/task.py", line 97, in _task_run_callback
    self._set_result(self.run())
  File "/usr/lib64/python3.6/site-packages/pyanaconda/modules/storage/installation.py", line 94, in run
    raise StorageInstallationError(str(e)) from None
pyanaconda.modules.common.errors.installation.StorageInstallationError: device path does not exist or is not writable

Fix confirmed using test compose which includes python3-blivet-3.4.0-2.el8.

python3-blivet-3.4.0-2.el8 is present in RHEL-8.5.0-20210716.n.0, moving to VERIFIED.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (python-blivet bug fix and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2021:4297