Provision of Rawhide in beaker fails with:

anaconda 44.11 exception report
Traceback (most recent call first):
  File "/usr/lib/python3.14/site-packages/dasbus/client/handler.py", line 509, in _handle_method_error
    raise exception from None
  File "/usr/lib/python3.14/site-packages/dasbus/client/handler.py", line 483, in _get_method_reply
    return self._handle_method_error(error)
  File "/usr/lib/python3.14/site-packages/dasbus/client/handler.py", line 450, in _call_method
    return self._get_method_reply(
  File "/usr/lib64/python3.14/site-packages/pyanaconda/ui/tui/spokes/installation_progress.py", line 134, in _on_installation_done
    self._task_proxy.Finish()
  File "/usr/lib/python3.14/site-packages/dasbus/signal.py", line 53, in emit
    callback(*args, **kwargs)
  File "/usr/lib/python3.14/site-packages/dasbus/client/handler.py", line 365, in _signal_callback
    callback(*unwrap_variant(parameters))
  File "/usr/lib/python3.14/site-packages/dasbus/client/handler.py", line 133, in _signal_callback
    callback(parameters, *callback_args)
pyanaconda.modules.common.errors.installation.BootloaderInstallationError: failed to write boot loader configuration

Local variables in innermost frame:
self: <dasbus.client.handler.ClientObjectHandler object at 0x7f8e44281c60>
error: g-io-error-quark: GDBus.Error:org.fedoraproject.Anaconda.BootloaderInstallationError: failed to write boot loader configuration (36)
name: org.fedoraproject.Anaconda.BootloaderInstallationError
cls: <class 'pyanaconda.modules.common.errors.installation.BootloaderInstallationError'>
message: failed to write boot loader configuration
exception: failed to write boot loader configuration



############
anaconda-tb-2te_aln2 contains:


DEBUG:blivet:syncing filesystem on /dev/vda2 mounted to /mnt/sysimage/boot
INFO:anaconda.modules.storage.bootloader.grub2:bootloader.py: mbr will be updated for grub2
INFO:program:Running in chroot '/mnt/sysroot'... grub2-install --no-floppy /dev/vda
INFO:program:Installing for i386-pc platform.
INFO:program:grub2-install: error: ../grub-core/kern/fs.c:grub_fs_probe:123:unknown filesystem.
DEBUG:program:Return code of grub2-install: 1
INFO:anaconda.modules.storage.bootloader.grub2:bootloader.py: used boot args: rd.lvm.lv=anaconda_kvm-08-guest29/root console=ttyS0,115200 
INFO:program:Running in chroot '/mnt/sysroot'... grub2-set-default 294d783ae6344a6c8225c7adddbdbc1e-6.18.0-65.fc44.x86_64
INFO:program:/usr/bin/grub2-editenv: warning: cannot probe fs for hd0,gpt2: ../grub-core/kern/fs.c:grub_fs_probe:123:unknown filesystem.
INFO:program:/usr/bin/grub2-editenv: warning: cannot probe fs for hd0,gpt2: ../grub-core/kern/fs.c:grub_fs_probe:123:unknown filesystem.
INFO:program:/usr/bin/grub2-editenv: warning: cannot probe fs for hd0,gpt2: ../grub-core/kern/fs.c:grub_fs_probe:123:unknown filesystem.
DEBUG:program:Return code of grub2-set-default: 0
INFO:program:Running in chroot '/mnt/sysroot'... grub2-mkconfig -o /boot/grub2/grub.cfg
INFO:program:/usr/bin/grub2-editenv: warning: cannot probe fs for hd0,gpt2: ../grub-core/kern/fs.c:grub_fs_probe:123:unknown filesystem.
INFO:program:Generating grub configuration file ...
INFO:program:/usr/bin/grub2-probe: error: ../grub-core/kern/fs.c:grub_fs_probe:123:unknown filesystem.
DEBUG:program:Return code of grub2-mkconfig: 1
ERROR:anaconda.modules.storage.bootloader.installation:Bootloader installation has failed: failed to write boot loader configuration
Traceback (most recent call last):
  File "/usr/lib64/python3.14/site-packages/pyanaconda/modules/storage/bootloader/grub2.py", line 436, in write
    self.install()
    ~~~~~~~~~~~~^^
  File "/usr/lib64/python3.14/site-packages/pyanaconda/modules/storage/bootloader/grub2.py", line 425, in install
    raise BootLoaderError("boot loader install failed")
pyanaconda.modules.storage.bootloader.base.BootLoaderError: boot loader install failed

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib64/python3.14/site-packages/pyanaconda/modules/storage/bootloader/installation.py", line 210, in run
    self._bootloader.write()
    ~~~~~~~~~~~~~~~~~~~~~~^^
  File "/usr/lib64/python3.14/site-packages/pyanaconda/modules/storage/bootloader/grub2.py", line 440, in write
    self.write_config()
    ~~~~~~~~~~~~~~~~~^^
  File "/usr/lib64/python3.14/site-packages/pyanaconda/modules/storage/bootloader/grub2.py", line 362, in write_config
    raise BootLoaderError("failed to write boot loader configuration")
pyanaconda.modules.storage.bootloader.base.BootLoaderError: failed to write boot loader configuration

Reproducible: Always