Describe the bug

A clear and concise description of what the bug is.

Steps To Reproduce

Steps to reproduce the behavior:

1. ...nix-shell -p nixops
2. ...
3. ...

Expected behavior

it builds!

Additional context

error: builder for '/nix/store/48sdc9gb26pb3prykylvy644mmsma0km-python2.7-ruamel-yaml-clib-0.2.4.drv' failed with exit code 1;

https://hydra.nixos.org/build/157985763

Notify maintainers

Metadata

Please run nix-shell -p nix-info --run "nix-info -m" and paste the result.

[user@system:~]$ nix-shell -p nix-info --run "nix-info -m"
 - system: `"x86_64-linux"`
 - host os: `Linux 5.10.70, NixOS, 21.05.20211003.7daf355 (Okapi)`
 - multi-user?: `yes`
 - sandbox: `yes`
 - version: `nix-env (Nix) 2.4pre20210922_bcd73eb`
 - channels(user): `"nixgl"`
 - channels(root): `"nixos-21.11pre332093.7fad01d9d5a"`
 - nixpkgs: `/nix/var/nix/profiles/per-user/root/channels/nixos`

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module: