Rename air logs --lines to --tail

acceptance/experimental/air/help/output.txt

@@ -59,10 +59,10 @@ Usage:
 Flags:
       --download-to string   Download all logs to this directory instead of printing
   -h, --help                 help for logs
-      --lines int            For completed runs, print the last N lines (default 10000)
       --minutes int          Fetch only logs from the last N minutes
       --node int             Fetch logs from this node
       --retry int            View logs from a specific retry attempt; -1 means latest (default -1)
+      --tail int             For completed runs, print the last N log lines (default 10000)
 
 Global Flags:
       --debug            enable debug logging

acceptance/experimental/air/logs-download/output.txt

@@ -9,8 +9,8 @@ Error: invalid --node 5: run has 2 node(s), indexed 0 to 1
 
 Exit code: 1
 
-=== download-to cannot be combined with --lines
->>> [CLI] experimental air logs 123 --download-to dl-logs --lines 50
-Error: --download-to writes complete logs, so it cannot be combined with --lines or --minutes
+=== download-to cannot be combined with --tail
+>>> [CLI] experimental air logs 123 --download-to dl-logs --tail 50
+Error: --download-to writes complete logs, so it cannot be combined with --tail or --minutes
 
 Exit code: 1

acceptance/experimental/air/logs-download/script

@@ -8,5 +8,5 @@ errcode trace $CLI experimental air logs 123 --download-to dl-logs
 title "download-to with an out-of-range node is rejected"
 errcode trace $CLI experimental air logs 123 --download-to dl-logs --node 5
 
-title "download-to cannot be combined with --lines"
-errcode trace $CLI experimental air logs 123 --download-to dl-logs --lines 50
+title "download-to cannot be combined with --tail"
+errcode trace $CLI experimental air logs 123 --download-to dl-logs --tail 50

acceptance/experimental/air/logs/output.txt

@@ -18,12 +18,12 @@ step 1
 step 2
 CUDA out of memory
 
-=== logs with --lines
->>> [CLI] experimental air logs 123 --lines 1
+=== logs with --tail
+>>> [CLI] experimental air logs 123 --tail 1
 CUDA out of memory
 
-=== logs with --lines 0 prints nothing
->>> [CLI] experimental air logs 123 --lines 0
+=== logs with --tail 0 prints nothing
+>>> [CLI] experimental air logs 123 --tail 0
 No logs available for run 123. Run terminated in state SUCCESS
 
 === logs from a specific retry
@@ -32,21 +32,21 @@ step 1
 step 2
 CUDA out of memory
 
-=== logs --lines and --minutes are mutually exclusive
->>> [CLI] experimental air logs 123 --lines 100 --minutes 30
-Error: cannot combine --lines with --minutes: --lines tails by line count, --minutes by time window
+=== logs --tail and --minutes are mutually exclusive
+>>> [CLI] experimental air logs 123 --tail 100 --minutes 30
+Error: cannot combine --tail with --minutes: --tail selects by line count, --minutes by time window
 
 Exit code: 1
 
-=== logs --lines and --minutes are mutually exclusive (json)
->>> [CLI] experimental air logs 123 --lines 100 --minutes 30 -o json
+=== logs --tail and --minutes are mutually exclusive (json)
+>>> [CLI] experimental air logs 123 --tail 100 --minutes 30 -o json
 {
   "v": 1,
   "ts": "[TIMESTAMP]",
   "error": {
     "code": "INVALID_ARGS",
     "kind": "PERMANENT",
-    "message": "cannot combine --lines with --minutes: --lines tails by line count, --minutes by time window",
+    "message": "cannot combine --tail with --minutes: --tail selects by line count, --minutes by time window",
     "retryable": false
   }
 }

acceptance/experimental/air/logs/script

@@ -7,20 +7,20 @@ trace $CLI experimental air logs 123 -o json
 title "logs with --minutes"
 trace $CLI experimental air logs 123 --minutes 30
 
-title "logs with --lines"
-trace $CLI experimental air logs 123 --lines 1
+title "logs with --tail"
+trace $CLI experimental air logs 123 --tail 1
 
-title "logs with --lines 0 prints nothing"
-trace $CLI experimental air logs 123 --lines 0
+title "logs with --tail 0 prints nothing"
+trace $CLI experimental air logs 123 --tail 0
 
 title "logs from a specific retry"
 trace $CLI experimental air logs 123 --retry 0
 
-title "logs --lines and --minutes are mutually exclusive"
-errcode trace $CLI experimental air logs 123 --lines 100 --minutes 30
+title "logs --tail and --minutes are mutually exclusive"
+errcode trace $CLI experimental air logs 123 --tail 100 --minutes 30
 
-title "logs --lines and --minutes are mutually exclusive (json)"
-errcode trace $CLI experimental air logs 123 --lines 100 --minutes 30 -o json
+title "logs --tail and --minutes are mutually exclusive (json)"
+errcode trace $CLI experimental air logs 123 --tail 100 --minutes 30 -o json
 
 title "invalid run id"
 errcode trace $CLI experimental air logs notanumber

experimental/air/cmd/logmlflow.go

@@ -79,7 +79,7 @@ var artifactDownloadClient = &http.Client{
 // per-node log directory, lists the chunk files, and walks them newest-first
 // until it has the requested tail, then prints oldest-first.
 //
-// The tail length is --lines, else the default cap. MLflow chunks are not
+// The tail length is --tail, else the default cap. MLflow chunks are not
 // time-indexed, so --minutes cannot restrict the window here.
 func mlflowLogFallback(ctx context.Context, w *databricks.WorkspaceClient, out io.Writer, req logRequest, status logRunStatus) (bool, error) {
 	if req.windowMinutes > 0 {

experimental/air/cmd/logs.go

@@ -21,7 +21,7 @@ import (
 func newLogsCommand() *cobra.Command {
 	var (
 		node       int
-		lines      int
+		tail       int
 		minutes    int
 		retry      int
 		downloadTo string
@@ -36,7 +36,7 @@ func newLogsCommand() *cobra.Command {
 	}
 
 	cmd.Flags().IntVar(&node, "node", 0, "Fetch logs from this node")
-	cmd.Flags().IntVar(&lines, "lines", 0, "For completed runs, print the last N lines (default 10000)")
+	cmd.Flags().IntVar(&tail, "tail", 0, "For completed runs, print the last N log lines (default 10000)")
 	cmd.Flags().IntVar(&minutes, "minutes", 0, "Fetch only logs from the last N minutes")
 	cmd.Flags().IntVar(&retry, "retry", -1, "View logs from a specific retry attempt; -1 means latest")
 	cmd.Flags().StringVar(&downloadTo, "download-to", "", "Download all logs to this directory instead of printing")
@@ -64,20 +64,20 @@ func newLogsCommand() *cobra.Command {
 
 		// A download always writes the full log, so a tail or time window would be
 		// silently dropped.
-		if downloadTo != "" && (cmd.Flags().Changed("lines") || minutes > 0) {
+		if downloadTo != "" && (cmd.Flags().Changed("tail") || minutes > 0) {
 			return renderError(ctx, cmd, "INVALID_ARGS", "PERMANENT", false,
-				errors.New("--download-to writes complete logs, so it cannot be combined with --lines or --minutes"))
+				errors.New("--download-to writes complete logs, so it cannot be combined with --tail or --minutes"))
 		}
 
-		// --lines (line tail) and --minutes (time window) answer the same question
+		// --tail (line tail) and --minutes (time window) answer the same question
 		// two ways, so reject both together rather than silently honoring one.
-		if lines > 0 && minutes > 0 {
+		if tail > 0 && minutes > 0 {
 			return renderError(ctx, cmd, "INVALID_ARGS", "PERMANENT", false,
-				errors.New("cannot combine --lines with --minutes: --lines tails by line count, --minutes by time window"))
+				errors.New("cannot combine --tail with --minutes: --tail selects by line count, --minutes by time window"))
 		}
-		if lines < 0 {
+		if tail < 0 {
 			return renderError(ctx, cmd, "INVALID_ARGS", "PERMANENT", false,
-				fmt.Errorf("invalid --lines %d: must be positive", lines))
+				fmt.Errorf("invalid --tail %d: must be positive", tail))
 		}
 		if minutes < 0 {
 			return renderError(ctx, cmd, "INVALID_ARGS", "PERMANENT", false,
@@ -98,11 +98,11 @@ func newLogsCommand() *cobra.Command {
 				fmt.Errorf("invalid JOB_RUN_ID %q: must be a positive integer", args[0]))
 		}
 
-		// -1 signals "unset" (use the default cap); an explicit --lines 0 stays 0
+		// -1 signals "unset" (use the default cap); an explicit --tail 0 stays 0
 		// and prints nothing.
 		tailLines := -1
-		if cmd.Flags().Changed("lines") {
-			tailLines = lines
+		if cmd.Flags().Changed("tail") {
+			tailLines = tail
 		}
 
 		// Only the streaming path prints resume guidance, so only it catches the

experimental/air/cmd/logs_test.go

@@ -30,6 +30,8 @@ func TestLogsCommandShape(t *testing.T) {
 	review := cmd.Flags().Lookup("review")
 	require.NotNil(t, review)
 	assert.True(t, review.Hidden)
+	assert.NotNil(t, cmd.Flags().Lookup("tail"))
+	assert.Nil(t, cmd.Flags().Lookup("lines"))
 }
 
 // runLogsCmd invokes the logs command's RunE with the given flags against a mock
@@ -55,16 +57,16 @@ func TestLogsFlagValidation(t *testing.T) {
 		wantMsg string
 	}{
 		{
-			name:    "lines and minutes are mutually exclusive",
+			name:    "tail and minutes are mutually exclusive",
 			args:    []string{"5"},
-			flags:   map[string]string{"lines": "100", "minutes": "10"},
-			wantMsg: "cannot combine --lines with --minutes",
+			flags:   map[string]string{"tail": "100", "minutes": "10"},
+			wantMsg: "cannot combine --tail with --minutes",
 		},
 		{
-			name:    "negative lines rejected",
+			name:    "negative tail rejected",
 			args:    []string{"5"},
-			flags:   map[string]string{"lines": "-1"},
-			wantMsg: "invalid --lines",
+			flags:   map[string]string{"tail": "-1"},
+			wantMsg: "invalid --tail",
 		},
 		{
 			name:    "negative minutes rejected",

experimental/air/cmd/logstream.go

@@ -23,7 +23,7 @@ const (
 	// before falling back to MLflow.
 	maxTransientFailures = 5
 	// defaultCompletedRunTailLines caps a completed run's output when neither
-	// --lines nor --minutes is set.
+	// --tail nor --minutes is set.
 	defaultCompletedRunTailLines = 10000
 	// seenRecordsCap bounds the dedup set, evicting oldest-inserted entries first.
 	seenRecordsCap = 100000
@@ -89,7 +89,7 @@ type logRequest struct {
 	// windowMinutes, when > 0, restricts the fetch to the last N minutes.
 	windowMinutes int
 	// tailLines caps a completed run's output to the last N lines. Negative means
-	// --lines was unset (use the default cap); 0 prints nothing.
+	// --tail was unset (use the default cap); 0 prints nothing.
 	tailLines int
 	// downloadTo, when set, writes logs to that directory instead of stdout.
 	downloadTo string
@@ -462,8 +462,8 @@ func (st *bricklensStreamer) drainStatic(toSec int64) (bool, error) {
 }
 
 // tailTarget is the number of lines a tail keeps. A negative tailLines means
-// --lines was unset, so use the default cap; 0 or more is taken literally (an
-// explicit --lines 0 prints nothing).
+// --tail was unset, so use the default cap; 0 or more is taken literally (an
+// explicit --tail 0 prints nothing).
 func (req logRequest) tailTarget() int {
 	if req.tailLines < 0 {
 		return defaultCompletedRunTailLines