Keep stdout to a command's output

.golangci.yml

@@ -96,6 +96,11 @@ linters:
         linters:
           - forbidigo
         text: user agent of the front end
+      # A test's child process stands in for a program whose stdout is its output.
+      - path: _test\.go
+        linters:
+          - forbidigo
+        text: stdout is a command's output
       - path: internal/tfstate/apiproxy/
         linters:
           - forbidigo
@@ -142,6 +147,14 @@ linters:
         - pattern: ^time\.Sleep$
           pkg: ^time$
           msg: a test waits on synctest's fake clock; run it inside synctest.Test and call synctest.Sleep
+        # stdout carries only what a command outputs, so that a pipe reads nothing else. Taking it
+        # from the command lets a test capture it.
+        - pattern: ^fmt\.Print(f|ln)?$
+          pkg: ^fmt$
+          msg: &stdout-only stdout is a command's output; write that to cmd.OutOrStdout(), and anything for a person through slog or cmd.ErrOrStderr()
+        - pattern: ^os\.Stdout$
+          pkg: ^os$
+          msg: *stdout-only
 
     gocritic:
       disabled-checks:

cmd/internal/output.go

@@ -56,7 +56,8 @@ func (f *OutputFlag) Type() string {
 }
 
 // WriteList leaves a listing that fails part way through unterminated, so that json output which
-// stopped early does not parse as a complete array.
+// stopped early does not parse as a complete array. ndjson has no end to leave out, so there only
+// the exit status tells a cut listing from a complete one.
 func (format OutputFormat) WriteList(w io.Writer, items iter.Seq2[jsontext.Value, error]) error {
 	list, err := format.listing()
 	if err != nil {

skills/meshstack-cli/SKILL.md

@@ -119,6 +119,8 @@ workspace identifier as meshPanel shows it (`metadata.name`, for example
 Commands for people (`auth status`, `profile list`) write Markdown. The others write one JSON array
 by default. For anything you consume yourself, use `-o ndjson`: one JSON object per line, so `jq`
 filters stream. A listing stops at 100 items unless you pass `--limit <n>` or `--limit unlimited`.
+A listing that fails part way leaves the lines it got and exits non-zero, which a pipe hides: run
+with `set -o pipefail`.
 
 ```sh
 meshstack bb list --limit unlimited -o ndjson | jq -r '...'