# Pastebin iSN2wjtM
$ sudo nixos-rebuild switch --upgrade
unpacking channels...
building Nix...
building the system configuration...
Traceback (most recent call last):
  File "/nix/store/71qjm4rjlxzz7z4dsxd8dndj9dlyil38-systemd-boot-builder.py", line 210, in <module>
    main()
  File "/nix/store/71qjm4rjlxzz7z4dsxd8dndj9dlyil38-systemd-boot-builder.py", line 197, in main
    write_entry(*gen, machine_id)
  File "/nix/store/71qjm4rjlxzz7z4dsxd8dndj9dlyil38-systemd-boot-builder.py", line 82, in write_entry
    initrd = copy_from_profile(profile, generation, "initrd")
  File "/nix/store/71qjm4rjlxzz7z4dsxd8dndj9dlyil38-systemd-boot-builder.py", line 57, in copy_from_profile
    copy_if_not_exists(store_file_path, "/boot%s" % (efi_file_path))
  File "/nix/store/71qjm4rjlxzz7z4dsxd8dndj9dlyil38-systemd-boot-builder.py", line 21, in copy_if_not_exists
    shutil.copyfile(source, dest)
  File "/nix/store/lp7x6ziq5b2zihgad0i8a28xxvz5vnrr-python3-3.6.4/lib/python3.6/shutil.py", line 122, in copyfile
    copyfileobj(fsrc, fdst)
  File "/nix/store/lp7x6ziq5b2zihgad0i8a28xxvz5vnrr-python3-3.6.4/lib/python3.6/shutil.py", line 82, in copyfileobj
    fdst.write(buf)
OSError: [Errno 28] No space left on device
warning: error(s) occurred while switching to the new configuration