lock: added troubleshooting doc link in error message (#4325)

dvc/lock.py

@@ -14,10 +14,13 @@
 
 DEFAULT_TIMEOUT = 3
 
+
 FAILED_TO_LOCK_MESSAGE = (
-    "cannot perform the command because another DVC process seems to be "
-    "running on this project. If that is not the case, manually remove "
-    "`.dvc/tmp/lock` and try again."
+    "Unable to acquire lock. Most likely another DVC process is running or "
+    "was terminated abruptly. Check the page {} for other possible reasons "
+    "and to learn how to resolve this."
+).format(
+    format_link("https://dvc.org/doc/user-guide/troubleshooting#lock-issue")
 )
 
 

tests/func/test_lock.py

@@ -1,6 +1,6 @@
 import pytest
 
-from dvc.lock import FAILED_TO_LOCK_MESSAGE, Lock, LockError
+from dvc.lock import Lock, LockError
 from dvc.main import main
 
 
@@ -18,6 +18,12 @@ def test_cli(tmp_dir, dvc, mocker, caplog):
     # patching to speedup tests
     mocker.patch("dvc.lock.DEFAULT_TIMEOUT", 0.01)
 
+    expected_error_msg = (
+        "Unable to acquire lock. Most likely another DVC process is "
+        "running or was terminated abruptly. Check the page "
+        "<https://dvc.org/doc/user-guide/troubleshooting#lock-issue> "
+        "for other possible reasons and to learn how to resolve this."
+    )
     with Lock(tmp_dir / dvc.tmp_dir / "lock"):
         assert main(["add", "foo"]) == 1
-    assert FAILED_TO_LOCK_MESSAGE in caplog.text
+    assert expected_error_msg in caplog.text