log: fix crash on removing log directory

`tt log -f` command crashes if log directory is removed.

CHANGELOG.md

@@ -20,6 +20,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Fixed
 
+- `tt log -f` crash on removing log directory.
+
 ### Changed
 
 ## [2.4.0] - 2024-08-07

cli/tail/tail.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/apex/log"
 	"github.com/fatih/color"
 	"github.com/nxadm/tail"
 )
@@ -163,7 +164,17 @@ func Follow(ctx context.Context, out chan<- string, logFormatter LogFormatter, f
 				t.Stop()
 				t.Wait()
 				return
-			case line := <-t.Lines:
+			case line, more := <-t.Lines:
+				if !more {
+					err := t.Stop()
+					if err != nil {
+						log.Error(err.Error())
+					} else {
+						log.Errorf("The log file %q is unavailable for reading. Exiting.")
+					}
+					close(out)
+					return
+				}
 				out <- logFormatter(line.Text)
 			}
 		}

test/integration/log/test_log.py

@@ -1,4 +1,5 @@
 import os
+import shutil
 import subprocess
 import time
 
@@ -253,3 +254,25 @@ def test_log_output_default_follow_want_zero_last(tt_cmd, mock_env_dir):
     assert 'app0:inst1' not in output
     assert 'app0:inst2' not in output
     assert 'app1:inst0' not in output
+
+
+def test_log__dir_removed_after_follow(tt_cmd, mock_env_dir):
+    cmd = [tt_cmd, 'log', '-f']
+    process = subprocess.Popen(
+        cmd,
+        cwd=mock_env_dir,
+        stderr=subprocess.STDOUT,
+        stdout=subprocess.PIPE,
+        text=True,
+    )
+
+    wait_for_lines_in_output(process.stdout,
+                             ['app0:inst0: line 19', 'app1:inst2: line 19',
+                              'app0:inst1: line 19', 'app1:inst1: line 19'])
+
+    var_dir = os.path.join(mock_env_dir, 'ie', 'app0', 'var')
+    assert os.path.exists(var_dir)
+    shutil.rmtree(var_dir)
+
+    assert process.wait(2) == 0
+    assert "Failed to detect creation of" in process.stdout.read()