[PATCH rtems-docs] user/hosts/windows.rst: flex needs to be installed for msys2

[Joel Sherrill]

Closes #4382.
---
 user/hosts/windows.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/user/hosts/windows.rst b/user/hosts/windows.rst
index fac1366..fd7ff55 100644
--- a/user/hosts/windows.rst
+++ b/user/hosts/windows.rst
@@ -156,6 +156,7 @@ The packages we require are:
 * python
 * mingw-w64-x86_64-python2
 * mingw-w64-x86_64-gcc
+* flex
 * git
 * bison
 * cvs
@@ -176,7 +177,7 @@ Install the packages using ``pacman``:
 .. code-block:: none
 
   $ pacman -S python mingw-w64-x86_64-python2 mingw-w64-x86_64-gcc \
-  bison cvs diffutils git make patch tar texinfo unzip
+  bison flex cvs diffutils git make patch tar texinfo unzip
   resolving dependencies...
   looking for conflicting packages...
       .... output shortened for brevity ....
-- 
1.8.3.1