AWS codebuild for windows: rename build directory

Author: kroening

buildspec-windows.yml

@@ -3,6 +3,13 @@ version: 0.2
 phases:
   install:
     commands:
+      - |
+        # Codebuild sets up a directory whose name changes with every build.
+        # We create a symlink with a fixed name to enable clcache to get cache hits.
+        Set-Location -Path "c:\codebuild\tmp"
+        New-Item -ItemType Junction -Name builddir -Value $env:CODEBUILD_SRC_DIR
+        Set-Location -Path "c:\codebuild\tmp\builddir"
+
       - choco install cyg-get -y --no-progress
       - cyg-get bash patch bison flex make wget perl
       - nuget install clcache -OutputDirectory "c:\tools" -ExcludeVersion -Version 4.1.0
@@ -11,7 +18,7 @@ phases:
     commands:
       - |
         $env:Path = "C:\tools\cygwin\bin;$env:Path"
-        C:\tools\cygwin\bin\bash -c "make -C src minisat2-download DOWNLOADER=wget"
+        bash -c "make -C src minisat2-download DOWNLOADER=wget"
 
       - |
         $env:Path = "C:\tools\cygwin\bin;c:\tools\clcache\clcache-4.1.0;$env:Path"