From 638806b2cc9c72dc5f65c95e4d071e84ed6851cc Mon Sep 17 00:00:00 2001
From: Kittywhiskers Van Gogh <63189531+kwvg@users.noreply.github.com>
Date: Thu, 27 May 2021 15:22:46 -0400
Subject: [PATCH] merge bitcoin#22088: improve note on choosing posix mingw32

---
 doc/build-windows.md | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/doc/build-windows.md b/doc/build-windows.md
index 1ac34c0189..6d2901c424 100644
--- a/doc/build-windows.md
+++ b/doc/build-windows.md
@@ -39,9 +39,26 @@ The first step is to install the mingw-w64 cross-compilation tool chain:
 
     sudo apt-get install g++-mingw-w64-x86-64 mingw-w64-x86-64-dev
 
-Ubuntu Focal 20.04 <sup>[1](#footnote1)</sup>:
+Next, set the default `mingw32 g++` compiler option to POSIX<sup>[1](#footnote1)</sup>:
 
-    sudo update-alternatives --config x86_64-w64-mingw32-g++ # Set the default mingw32 g++ compiler option to posix.
+```
+sudo update-alternatives --config x86_64-w64-mingw32-g++
+```
+
+After running the above command, you should see output similar to that below.
+Choose the option that ends with `posix`.
+
+```
+There are 2 choices for the alternative x86_64-w64-mingw32-g++ (providing /usr/bin/x86_64-w64-mingw32-g++).
+
+  Selection    Path                                   Priority   Status
+------------------------------------------------------------
+  0            /usr/bin/x86_64-w64-mingw32-g++-win32   60        auto mode
+* 1            /usr/bin/x86_64-w64-mingw32-g++-posix   30        manual mode
+  2            /usr/bin/x86_64-w64-mingw32-g++-win32   60        manual mode
+
+Press <enter> to keep the current choice[*], or type selection number:
+```
 
 Once the toolchain is installed the build steps are common: