Reuse CI machine's msys64 when possible

scripts/msys2.cmd

@@ -2,7 +2,7 @@
 setlocal
 set MSYSTEM=MINGW64
 set CHERE_INVOKING=1
-set emacs_build_dir=%~dp0
-set emacs_build_dir=%emacs_build_dir:~0,-9%
-set msys2_dir=%emacs_build_dir%\msys64
+set emacs_build_dir=%~dp0..
+set msys2_dir=c:\msys64
+if not exist %msys2_dir%\ (set msys2_dir=%emacs_build_dir%\msys64)
 %msys2_dir%\usr\bin\bash.exe -leo pipefail %*

scripts/setup-msys2.ps1

@@ -3,31 +3,43 @@
 # https://github.com/msys2/setup-msys2/blob/master/main.js
 
 $emacs_build_dir = $PSScriptRoot + '\..'
-$msys2_dir = $emacs_build_dir + '\msys64'
-$inst_url = 'https://github.com/msys2/msys2-installer/releases/download/2020-11-09/msys2-base-x86_64-20201109.sfx.exe'
-$installer_checksum = 'f8a05b9353c42735521f393497dbbd0ce4db1a9de79ee1f6ef224bc9fae144b7'
-$installer = ${msys2_dir} + '\msys2-base.exe'
+$msys2_dir = 'c:/msys64'
+if (!(Test-Path $msys2_dir))
+{
+    $msys2_dir = $emacs_build_dir + '\msys64'
+}
+$inst_url = 'https://github.com/msys2/msys2-installer/releases/download/2021-04-19/msys2-base-x86_64-20210419.sfx.exe'
+$installer_checksum = '1f2cfd8e13b0382096e53ead6fd52d0b656a1f81e1b5d82f44cb4ce8ab68755e'
+$installer = $msys2_dir + '\msys2-base.exe'
 
-if ( !(Test-Path ${msys2_dir}) ) {
-    echo "Creating MSYS2 directory ${msys2_dir}"
-    mkdir ${msys2_dir}
+if (!(Test-Path $msys2_dir))
+{
+    echo "Creating MSYS2 directory $msys2_dir"
+    mkdir $msys2_dir
 }
-if ( !(Test-Path ${msys2_dir}\msys2_shell.cmd) ) {
-    if ( !(Test-Path ${installer}) ) {
+
+if (!(Test-Path ${msys2_dir}\msys2_shell.cmd))
+{
+    if (!(Test-Path ${installer}))
+    {
         echo "Downloading MSYS2 installer to ${installer}"
         [Net.ServicePointManager]::SecurityProtocol = "tls12, tls11, tls"
         Invoke-WebRequest -Uri $inst_url -OutFile ${installer}
     }
+
     $checksum = (Get-FileHash ${installer} -Algorithm SHA256)[0].Hash
-    if ( $checksum -ne $installer_checksum ) {
+    if ($checksum -ne $installer_checksum)
+    {
         echo "Downloaded file $installer has checksum $checksum"
         echo "which differs from $installer_checksum"
     }
+
     echo "Emacs build root: $emacs_build_dir"
     cd "${emacs_build_dir}"
     echo "Unpack MSYS2"
     & ${installer} -y
 
+    cd "${emacs_build_dir}"
     # Reduce time required to install packages by disabling pacman's disk space checking
     .\scripts\msys2.cmd -c 'sed -i "s/^CheckSpace/#CheckSpace/g" /etc/pacman.conf'
     # Force update packages
@@ -42,7 +54,9 @@ if ( !(Test-Path ${msys2_dir}\msys2_shell.cmd) ) {
     # Final upgrade
     echo "Final upgrade"
     .\scripts\msys2.cmd -c 'pacman --noprogressbar --noconfirm -Syuu'
-    # Install packages required by emacs-build
-    echo "Install essential packages"
-    .\scripts\msys2.cmd -c 'pacman --noprogressbar --needed --noconfirm -S git unzip zip base-devel mingw-w64-x86_64-toolchain'
 }
+
+cd "${emacs_build_dir}"
+# Install packages required by emacs-build
+echo "Install essential packages"
+.\scripts\msys2.cmd -c 'pacman --noprogressbar --needed --noconfirm -S git unzip zip base-devel mingw-w64-x86_64-toolchain'