./tools/ctl --help is not as helpful as it could be

[msuozzo]

Using golang's built-in flags package interacts poorly with Cobra when providing --help on the command.

We can fix this by using Cobra's native flags (pflags) but the associated refactor isn't a clear positive code-wise. Not a high priority but worth noting this drawback.

Details

go run ./tools/ctl provides the "good" Cobra-based help:

$ go run ./tools/ctl
A debugging tool for OSS-Rebuild

Usage:
  ctl [command]

Available Commands:
  completion  Generate the autocompletion script for the specified shell
  get-results Analyze rebuild results
  help        Help about any command
  list-runs   List runs
  run-bench   Run benchmark
  run-one     Run benchmark
  tui         A terminal UI for the OSS-Rebuild debugging tools

Flags:
  -h, --help   help for ctl

Use "ctl [command] --help" for more information about a command.

...but go run ./tools/ctl --help shows the flat native flag help:

$ go run ./tools/ctl --help
Usage of /tmp/go-build999803442/b001/exe/ctl:
  -api string
        OSS Rebuild API endpoint URI
  -artifact string
        the artifact name
  -bench string
        a path to a benchmark file. if provided, only results from that benchmark will be fetched
  -benchmark-dir string
        a directory with benchmarks to work with
  -clean
        whether to apply normalization heuristics to group similar verdicts
....

Fix

- cmd.Flags().AddGoFlag(flag.Lookup(...))
+ cmd.Flags().StringVar(...)

The usage of the flag values would need to be mediated by either global variables (as flag definitions currently are) or built into cmd-specific data types passed in to the cmd defintions.