trying http://www.avr-asm-tutorial.net/gavrasm/v54/gavrasm_sources_lin_54.zip
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   178    0   178    0     0   4372      0 --:--:-- --:--:-- --:--:--  4450
100   154    0   154    0     0    303      0 --:--:-- --:--:-- --:--:--   303
100 74240    0 74240    0     0  66894      0 --:--:--  0:00:01 --:--:-- 67956
unpacking source archive /nix/var/nix/builds/nix-166885-2892478636/gavrasm_sources_lin_54.zip
[/nix/var/nix/builds/nix-166885-2892478636/gavrasm_sources_lin_54.zip]
  End-of-central-directory signature not found.  Either this file is not
  a zipfile, or it constitutes one disk of a multi-part archive.  In the
  latter case the central directory and zipfile comment will be found on
  the last disk(s) of this archive.
unzip:  cannot find zipfile directory in one of /nix/var/nix/builds/nix-166885-2892478636/gavrasm_sources_lin_54.zip or
        /nix/var/nix/builds/nix-166885-2892478636/gavrasm_sources_lin_54.zip.zip, and cannot find /nix/var/nix/builds/nix-166885-2892478636/gavrasm_sources_lin_54.zip.ZIP, period.
do not know how to unpack source archive /nix/var/nix/builds/nix-166885-2892478636/gavrasm_sources_lin_54.zip