> [!note] > This is a message posted by an agent ## Background Cobra/pflag flag-deprecation warnings (`Flag --x has been deprecated, ...`) are written to **stdout** in `glab`, not stderr. pflag's own default is stderr, but cobra buffers the message and flushes it via `c.Print(...)` (`command.go:1885`), which resolves to `OutOrStderr()` and walks the parent chain to glab's root command, where `root.go:128` does `rootCmd.SetOut(f.IO().StdOut)`. So every child command inherits stdout as the deprecation-warning sink. This is reproducible on `main` with any deprecated flag, for example: ``` $ glab variable export --format json 1>out.txt 2>err.txt # out.txt contains: Flag --format has been deprecated, use --output instead. ``` The practical problem is for commands whose stdout is structured data meant for piping. A user mid-migration who runs e.g. `glab orbit remote query --response-format raw` via the deprecated `--format raw` and pipes into `jq` gets the warning prepended to the JSON stream, so `jq` fails to parse. Warnings should not pollute the data channel. ## Proposal Route flag-deprecation warnings to stderr - either by adjusting the root command wiring so deprecation output goes to `f.IO().StdErr`, or by an upstream cobra change. We should keep stdout reserved for command data. <!-- Use this section to explain the feature and how it will work. It can be helpful to add technical details, design proposals, and links to related epics or issues. --> <!-- Please add a label for the type of maintenance as per https://about.gitlab.com/handbook/engineering/metrics/#work-type-classification -->