Add faster way to load kubectl bash completions in shell.nix

[neumantm]

No description provided.

[haslersn]

The nix-shell build fails on my machine with Lorri:

Jan 17 22:25:18.471 INFO build message, message: BuildEvent(Started { nix_file: NixFile("/home/haslersn/projects/neumantm/stuvus_config/shell.nix"), reason: ProjectAdded(NixFile("/home/haslersn/projects/neumantm/stuvus_config/shell.nix")) }), expr: /home/haslersn/projects/neumantm/stuvus_config/shell.nix
Jan 17 22:25:23.742 INFO build message, message: BuildEvent(Failure { nix_file: NixFile("/home/haslersn/projects/neumantm/stuvus_config/shell.nix"), failure: Exit { cmd: "\"nix-build\" \"--out-link\" \"/tmp/.tmpdRjuck/result\" \"--\" \"/tmp/.tmpE9OcfD/result\"", status: Some(100), logs: [LogLine("these derivations will be built:"), LogLine("  /nix/store/jhgacgc6bpf7q4dw27xvz4d06rjp571p-lorri-keep-env-hack-stuvus_config-shell.drv"), LogLine("building \'/nix/store/jhgacgc6bpf7q4dw27xvz4d06rjp571p-lorri-keep-env-hack-stuvus_config-shell.drv\'..."), LogLine("/dev/fd/63: line 12982: complete: command not found"), LogLine("builder for \'/nix/store/jhgacgc6bpf7q4dw27xvz4d06rjp571p-lorri-keep-env-hack-stuvus_config-shell.drv\' failed with exit code 127"), LogLine("error: build of \'/nix/store/jhgacgc6bpf7q4dw27xvz4d06rjp571p-lorri-keep-env-hack-stuvus_config-shell.drv\' failed")] } }), expr: /home/haslersn/projects/neumantm/stuvus_config/shell.nix

[neumantm]

Caused by target/lorri#492