From 0106842af437923eb92d5077105631dc575ed51b Mon Sep 17 00:00:00 2001
From: Heiko Thiel <heiko.thiel@hpi.de>
Date: Wed, 23 Jun 2021 17:24:09 +0200
Subject: Help: Clarify condition of tree command from source_group.

---
 Help/command/source_group.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Help/command/source_group.rst b/Help/command/source_group.rst
index a4b5bf1..83ae286 100644
--- a/Help/command/source_group.rst
+++ b/Help/command/source_group.rst
@@ -22,7 +22,8 @@ The options are:
  CMake will automatically detect, from ``<src>`` files paths, source groups
  it needs to create, to keep structure of source groups analogically to the
  actual files and directories structure in the project. Paths of ``<src>``
- files will be cut to be relative to ``<root>``.
+ files will be cut to be relative to ``<root>``. The command fails if the
+ paths within ``src`` do not start with ``root``.
 
 ``PREFIX``
  .. versionadded:: 3.8
-- 
cgit v0.12