[PATCH] user: add a warning not to use special characters in pathnames

[Joel Sherrill]

From: Marçal Comajoan Cara <mcomajoancara at gmail.com>

Spaces and other specical characters in pathnames break builds of any
software packages using GNU make.

All of the GNU tools and RTEMS use make and this breaks builds. This
is a long standing known issue with GNU make, which can't handle spaces
in pathnames:

https://savannah.gnu.org/bugs/?712

This work was part of GCI 2018.

Probably closes #3450.
---
 user/hosts/os.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/user/hosts/os.rst b/user/hosts/os.rst
index 82ff4de..d9fe943 100644
--- a/user/hosts/os.rst
+++ b/user/hosts/os.rst
@@ -63,6 +63,13 @@ proven over the years to be difficult to manage in production systems.
     means it is searched first and the RTEMS needed versions of the tools are
     used.
 
+.. warning::
+
+    Do not put spaces or special characters in the directories you use to build
+    RTEMS. Many of the packages built by the RSB use GNU *make*, which cannot
+    handle spaces in pathnames. If there is a space in the pathname the build
+    will fail. Special characters are also likely to confuse build systems.
+
 .. note::
 
     RSB and RTEMS have a matching *git branch* for each version of RTEMS. For
-- 
1.8.3.1