First off, thanks for your help so far! > Did you use 1.0.1 image or a more recent one? I was using the Guix System 1.0.1 x86_64 image here: https://guix.gnu.org/download/ > Did you mount your EFI partition to "/mnt/boot/efi" before > starting the > install? Yep. Not mounting it yields a different error (cannot find canonical path of /mnt/boot/efi) I'll also confirm I'm setting the esp flag on the partition. > Now, if you could try again with: > > * The 1.1.0-rc2 release available here[2]. - The graphical installer displays normal behavior up to when making the partitions, where it resets the installation without displaying an error - Installation through TTY has the same behavior as before, efibootmgr failed to register the boot entry: Input/output error > * This custom release[3]: 1.1.0-rc2 + the patch suggested by > Danny for > partitions > 1TiB. - Graphical installation has an oddity, my Samsung drive has disappeared from the disk selection in both guided and manual partitioning - Strangely, my WD Blue 2TB drive (also an SSD) with the NixOS installation shows up just fine - While it is possible to access the Samsung drive from the TTY, and even wipe it/make new partitions, trying to populate the partitions with filesystems will result in them saying they're in use or already mounted. I suspect this is also why it's not showing up in the graphical installation.