these 2 derivations will be built:
  /nix/store/8c9ghhai1i1irrl4npw9lnghi3yjb7d0-devshell-dir.drv
  /nix/store/h2z7n2mwqymf0ppnr285mwyf8bg4rj4y-devshell.drv
building '/nix/store/8c9ghhai1i1irrl4npw9lnghi3yjb7d0-devshell-dir.drv'
devshell-dir> created 471 symlinks in user environment
building '/nix/store/h2z7n2mwqymf0ppnr285mwyf8bg4rj4y-devshell.drv'