What's the NixOS experience like? I haven't tried in a while but my phone would get stuck on the NixOS splash screen. How did you install yours? So you have a public repo I could look at?
We can unxz that, then trim the leading bytes according to the Nar file format (described in Dolstra's PhD thesis, figure 5.2, page 93 https://edolstra.github.io/pubs/phd-thesis.pdf ). Since this .nar only contains one file, we can just ignore the header bytes (they're padded to multiples of 8 bytes; I think in this case we need to skip the first 96 bytes). We can do this while dd-ing the image to our SD card, e.g.
This is quite convoluted, but I did this while stuck on a crappy Chromebook ;)
Note that the above images have no usable user accounts. I mounted the resulting SD card and edited the /etc/shadow file to enable root login without a password. I could then log in to a text console, using an external keyboard :)
