Include UTxO HD installation/usage instructions for Windows in READMEs.

@jasagredo and @layogeshsajanikar have provided update instructions for
Windows, which are based on the build steps on their Windows
machines/VMs.

Author: jorisdral

doc/getting-started/building-the-node-on-windows.md

@@ -2,8 +2,7 @@
 
 This document explains how to build a __DEVELOPMENT__ version of the `cardano-node`. Note that this is *not* for building a __PRODUCTION__ version of the node.
 
-We recommend installing and using `git-bash` for development purposes, which is `git` when installed with `choco install git`.
-
+See [install.md](./install.md) for a more thorough explanation of the dependencies and packages that have to be installed to run a node. Although the installation instructions in that document are aimed at building on Linux, large parts of the text are interesting to Windows users as well.
 
 ## Install the Haskell environment
 
@@ -18,90 +17,173 @@ ghcup set ghc 8.10.7
 ghcup set cabal 3.6.2.0
 ```
 
-Alternatively, with `ghcup tui` you can pick the specific versions of the tools that you want to install, in particular you should have installed and set:
-- `cabal >= 3.6.2.0`
-- `GHC >= 8.10.7`
-
-## Install pkg-config
-
-To start building on `Windows`, you will need to install and configure specific tools outlined below. We recommend using [chocolatey](https://chocolatey.org), which provides the `choco` command to install some of these tools. You can run all the instructions that invoke `choco` in bash with root privileges.
+## Install MSYS2 and basic dependencies
 
+### GHCUP and MSYS2
+​
+Note that the GHCUP comes with its own installation for MSYS2, and it can be used to build `cardano-node`. You can start the MSYS2 shell with
+```cmd
+<ghcup-path>\msys64\msys2_shell.cmd -defterm -here -no-start -mingw64
+```
+​
+Make sure to enable `mingw64` subsystem. It is also possible to enable `mingw64` subsystem by
+​
 ```bash
-choco install pkgconfiglite
+source shell mingw64
+```
+​
+​
+The MSYS2 shell is bundled with `pacman` package manager. `GHC` is bundled with `gcc` for `mingw`. Configure your environment to use this tool-chain.
+​
+```bash
+pacman -Syu
+pacman -S --needed base-devel automake git
+export PATH=$PATH:/mingw64/bin:<ghcup-path>/bin:<ghcup-path>/ghc/<ghc-version>/mingw/bin
+```
+​
+Alternatively, you can update the `mingw64` tool-chain, that adds number of packages including latest `gcc`. This may give rise to `crt` linker error. Please read the [section - global cabal configuration](#global-cabal-configuration) to mitigate the error.
+​
+```bash
+pacman -S mingw-w64-x86_64-toolchain
 ```
 
-## Install vcpkg
+### Installing MSYS independently
 
-You will first need to install `vcpkg` to proceed installing necessary libraries (which is the next step).
+Go to [the MSYS2 website](https://www.msys2.org/) and follow its instructions to install MSYS2. It will also install `pacman`. Then, update and upgrade all `pacman` packages and install basic dependencies:
+​
+```
+pacman -Syu
+pacman -S --needed base-devel mingw-w64-x86_64-toolchain git
+```
 
-For this, use `git`(which you can also install using `choco`) and follow [these instructions](https://github.com/microsoft/vcpkg#quick-start-windows).
+## Installing and configuring third party libraries
+You can use `vcpkg`, or `pacman` or both to install third party libraries. Following are the dependencies for `cardano-node`.
+
+| package   | `vcpkg`   | `pacman`                   |  Remarks
+|-----------|-----------|----------------------------|--------------------------------------
+| libsodium | libsodium | mingw-w64-x86_64-lmdb      |
+| lmdb      | lmdb      | mingw-w64-x86_64-libsodium |
+| secp256k1 | secp256k1 | __not available__          | `vcpkg` package is not complete.
+| openssl   | openssl   | mingw-w64-x86_64-openssl   |
+|-----------|-----------|----------------------------|--------------------------------------
+
+### Using __vcpkg__
+- Install `vcpkg` for MSYS2 with instruction given [here](https://vcpkg.io/en/docs/users/mingw.html)
+- Set following variables for installing libraries
+  ```bash
+  export VCPKG_DEFAULT_TRIPLET=x64-mingw-static
+  export VCPKG_DEFAULT_HOST_TRIPLET=x64-mingw-dynamic
+  ```
+- You can also use `x64-mingw-dynamic` for `VCPKG_DEFAULT_TRIPLET`, if you'd like to use shared libraries
+- Install libraries
+  ```bash
+  vcpkg install libsodium
+  vcpkg install openssl
+  vcpkg install lmdb
+  ```
+- __cardano-crypto-class__ uses several features of `secp256k1` that are not compiled into `vcpkg` package. Hence it needs to be compiled separately.
+- `vcpkg` generates `pkg-config` when it can. It generates configuration for `openssl`. To avoid mixing configurations with existing system, you can use following to install packages
+  ```bash
+  PATH="${PATH/:\/usr\/bin:\/bin:/:}:/ming64/bin" ./vcpkg.exe install <pkg-name>
+  ```
+  + Note that packages will be generated at `<vc-pkg>/installed/${VCPKG_DEFAULT_TRIPLET}/lib/pkgconfig`.
+
+### Using __MSYS2 pacman__
+
+You can search for packages [here](https://packages.msys2.org/)
+
+- Install dependencies as below
+  ```bash
+  pacman -S mingw-w64-x86_64-libsodium
+  pacman -S mingw-w64-x86_64-lmdb
+  pacman -S mingw-w64-x86_64-openssl
+  ```
+
+### Install Secp256k1
+
+You can use `secp256k1` either by downloading from hydra. Or by downloading from [github](https://github.com/bitcoin-core/secp256k1)
 
-You can now install `libsodium`, `openssl`, `secp256k1` and `lmdb` with the following commands:
-```bash
-./vcpkg install --triplet x64-windows libsodium
-./vcpkg install --triplet x64-mingw-dynamic openssl
-./vcpkg install secp256k1
-./vcpkg install lmdb
+```
+pacman -S unzip
+curl https://hydra.iohk.io/job/Cardano/haskell-nix/windows-secp256k1/latest/download/1 -o secp256k1.zip
+mkdir secp256k1
+cd secp256k1/
+unzip ../secp256k1.zip
+cp -r * /mingw64
 ```
 
-## Create libsodium.pc file (and others)
+If `unzip` complains that `../secp256k1.zip` is not a zip file, unzip the
+file manually in the explorer by choosing the option to unzip from the
+right-click menu.
 
-To find system dependencies like `libsodium`, `cabal` uses `pkg-config`. On Windows, you will need to create the `libsodium.pc` description file in a correct directory.
+### Managing package configuration
+Make sure that package configurations are correectly installed. If you are using chocolatey or other tool, it may be possible that more than one `pkg-config` tools are installed. You are encouraged to use `pkg-config` that __MSYS2__ has to minimize the error.  Also make sure that the pkg configuration are discoverable by checking that `pkg-config --list-all` lists all the installed packages.
+​
+Note that the pkg-config will only look in the paths pointed to by `pkg-config --variable pc_path pkg-config`. Also check if pkg-config correctly displays library path, by checking `pkg-config --variable libdir <pkg-name>`. In case, the path is incorrectly displayed, modify the file `pkg-config --path <pkg-name>` to correct the path.
 
-In one of the paths reported by:
-```bash
-pkg-config --variable pc_path pkg-config
-```
-create `libsodium.pc` file, which contains:
 
-```
-libdir=VCPKG_PATH/installed/x64-windows/bin
-includedir=VCPKG_PATH/installed/x64-windows/include
-
-Name: libsodium
-VERSION: LIBSODIUM_VERSION
-Description: libsodium library
-Cflags: -I${includedir}/sodium
-Libs: -L${libdir} -llibsodium
-```
-> Note that you need to replace `VCPKG_PATH` with the absolute path, where you use `vcpkg`, and `LIBSODIUM_VERSION` with the version number of `libsodium` which was installed on your system. Please verify that the paths above contain `libsodium.dll` file and headers.
 
-> Also, you cannot use `prefix=` in the `libsodium.pc` file. This might be changed for some other directory, `pkg-config` provides a switch to use the provided `prefix`, but there is no way to instruct `cabal` to do so.
+## Global `cabal` configuration
 
-Follow the same procedure of creating `.pc` files for `openssl`, `secp256k1` and `lmdb`.
+Modify the following entries to your global `cabal` config file in your
+`\path\to\cabal\` directory, such that they look like this:
 
-Finally, ensure that
 ```
-pkg-config --list-all
+-- extra-include-dirs:
+extra-lib-dirs:  C:\ghcup\ghc\8.10.7\mingw\x86_64-w64-mingw32\lib
+extra-prog-path: C:\ghcup\bin,
+                 path\to\cabal\bin
 ```
-lists all packages: `libsodium`, `openssl`, `secp256k1` and `lmdb`.
 
+Depending on the installation procedure, the path to your `\path\to\cabal\` directory could be `C:\Users\<username>\AppData\Roaming\cabal`).
+
+> Note: The instructions in this section are a workaround for a
+> [GHCup bug](https://github.com/msys2/MINGW-packages/issues/10837#issuecomment-1047105402).
 
-## `cabal` configuration
+## Downloading the source code for cardano-node
 
-Go to the directory, where you cloned the `cardano-node` repository and add the command below to your `cabal.project.local` file (if you don't already have it, create one):
+Create a working directory for your builds:
 
+```bash
+mkdir -p ~/src
+cd ~/src
 ```
-max-backjump: 5000
-reorder-goals: True
 
-package cardano-crypt-praos
-  flags: -external-libsodium-vrf
+Download the Cardano node sources:
 
-extra-lib-dirs: "VCPKG_PATH\\installed\\x64-windows\\bin"
-extra-include-dirs: "VCPKG_PATH\\installed\\x64-windows\\include"
+```bash
+git clone https://github.com/input-output-hk/cardano-node.git
 ```
 
-The final step is to add `VCPKG_PATH/installed/x64-windows/bin` to the `PATH` variable. Since we are using `git-bash`, you can do this with:
+Change the working directory to the downloaded source code folder:
 
+```bash
+cd cardano-node
 ```
-export PATH="VCPKG_PATH/installed/x64-windows/bin:${PATH}"
+
+## Local `cabal` configuration
+
+Add the following to the `cabal.project.local` file (if you don't already have it, create one) in the source code folder:
+
 ```
-*Remember to substitute `VCPKG_PATH` with the real path.*
+package lmdb
+  extra-lib-dirs:     "<lmdb-library-path> Or standard path E.g. C:\\msys64\\mingw64\\include or C:/tools/ghcup/msys64/mingw64/lib"
+  extra-include-dirs: "<lmdb-library-path> Or standard path E.g. C:\\msys64\\mingw64\\include or C:/tools/ghcup/msys64/mingw64/include"
+
+-- If pkg-config is available, use it.
+package HsOpenSSL
+  flags: +use-pkg-config
+
+package cardano-crypt-praos
+  flags: -external-libsodium-vrf
+```
+
+## Building and installing the node
 
 You can now build the node with:
 
 ```bash
+cabal update
 cabal build --builddir /c/dist exe:cardano-node
 ```
 
@@ -111,3 +193,9 @@ You can now verify whether the node runs:
 ```bash
 cabal run --builddir /c/dist exe:cardano-node -- run --help
 ```
+
+## Notes
+
+### Speed up compilation
+
+`reorder-goals` can affect the compilation time negatively. You can disable `reorder-goals` by setting it to `False` in `cabal.project.local`.