$ nix-build -p htop
these derivations will be built:
  /nix/store/vfyx6xjnzia0pb5z318h6ml62qw5w333-shell.drv
building path(s) ‘/nix/store/xpg5ldkdravf4xlaszs358317w57w6lm-shell’
builder for ‘/nix/store/vfyx6xjnzia0pb5z318h6ml62qw5w333-shell.drv’ failed to produce output path ‘/nix/store/xpg5ldkdravf4xlaszs358317w57w6lm-shell’
error: build of ‘/nix/store/vfyx6xjnzia0pb5z318h6ml62qw5w333-shell.drv’ failed