mail tool cannot find opensmtpd sendmail

[agreif]

Issue description

echo foo | mail -s test1 me@myserver.de
mail: Cannot open mailer: No such file or directory
mail: cannot send message: No such file or directory

seems that when using opensmtpd, the sendmail is not wrapped:

# which sendmail
/run/current-system/sw/bin/sendmail

# ll /run/wrappers/bin/sendmail
ls: cannot access '/run/wrappers/bin/sendmail': No such file or directory

Steps to reproduce

install stable 18.03 with the packages:
opensmtpd and
mailutils

then send mail as above from the command line

Technical details

# nix-shell -p nix-info --run "nix-info -m"
these paths will be fetched (0.82 MiB download, 4.38 MiB unpacked):
  /nix/store/5hszvi0hczzh25mmsz5rkb9qa758c10p-bash-4.4-p12-dev
  /nix/store/9bkj2zjc8jdzwgwdwb5d890hrhrk9d3g-bash-4.4-p12-dev
  /nix/store/bkx6rzqciq0sdn1z5liard33ffvv1n3s-bash-4.4-p12-doc
  /nix/store/d5ki460cwwydf93f31is95sqpcf334r4-bash-4.4-p12-info
  /nix/store/f1rp3j71id6g6zcmiafrksmw1cgydl9k-bash-4.4-p12-doc
  /nix/store/fskpf2pdlgn4gm2kay7lfbw1cmjil6s3-bash-4.4-p12-man
copying path '/nix/store/bkx6rzqciq0sdn1z5liard33ffvv1n3s-bash-4.4-p12-doc' from 'https://cache.nixos.org'...
copying path '/nix/store/f1rp3j71id6g6zcmiafrksmw1cgydl9k-bash-4.4-p12-doc' from 'https://cache.nixos.org'...
copying path '/nix/store/d5ki460cwwydf93f31is95sqpcf334r4-bash-4.4-p12-info' from 'https://cache.nixos.org'...
copying path '/nix/store/fskpf2pdlgn4gm2kay7lfbw1cmjil6s3-bash-4.4-p12-man' from 'https://cache.nixos.org'...
copying path '/nix/store/5hszvi0hczzh25mmsz5rkb9qa758c10p-bash-4.4-p12-dev' from 'https://cache.nixos.org'...
copying path '/nix/store/9bkj2zjc8jdzwgwdwb5d890hrhrk9d3g-bash-4.4-p12-dev' from 'https://cache.nixos.org'...
 - system: `"x86_64-linux"`
 - host os: `Linux 4.14.40, NixOS, 18.03.132339.c3da680b114 (Impala)`
 - multi-user?: `yes`
 - sandbox: `no`
 - version: `nix-env (Nix) 2.0.1`
 - channels(root): `"nixos-18.03.132339.c3da680b114"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs`

[agreif]

I could solve the problem with wrapping sendmail myself:

  services.mail.sendmailSetuidWrapper = {
    program = "sendmail";
    source = "${pkgs.opensmtpd}/sbin/smtpctl";
    setuid = false;
    setgid = false;
  };

But I leave this issue open, because I think it should happen after the installation of opensmtpd automaticaly ... or I misunderstand the concept?

[Ekleog]

@agreif I have opened #54049 that should hopefully fix this without the need for the wrapped sendmail. Could you check it works for you? :)