this derivation will be built:
  /nix/store/3yaxk66fcq0jcsfxk2h3rmsl81xic7qa-spec-nixfmt.drv
this path will be fetched (0.4 KiB download, 0.7 KiB unpacked):
  /nix/store/nxywk9j968v5sirnp11nq5amgp1jgk59-writable-tmpdir-as-home-hook
building '/nix/store/3yaxk66fcq0jcsfxk2h3rmsl81xic7qa-spec-nixfmt.drv'
spec-nixfmt> invalid/a.nix:1:7:
spec-nixfmt>   |
spec-nixfmt> 1 | { a = ;
spec-nixfmt>   |       ^^
spec-nixfmt> unexpected ";<newline>"
spec-nixfmt> expecting expression
spec-nixfmt> 
spec-nixfmt> invalid/a.nix:1:7:
spec-nixfmt>   |
spec-nixfmt> 1 | { a = ;
spec-nixfmt>   |       ^^
spec-nixfmt> unexpected ";<newline>"
spec-nixfmt> expecting expression
spec-nixfmt> 

upload niks3: ok