Fix the x64 Windows build environment used by the buildbots. %VS90COMNTOOLS%\vsvars32.bat is fine for 32-bit builds, but doesn't work for x64 builds, regardless of /MACHINE:AMD64 and /USECL:MS_OPTERON flags passed to cl.exe. Launch the x86_64 cross compilation environment via '%VS90COMNTOOLS%\..\..\VC\vcvarsall.bat x86_amd64'. I don't have access to any systems *without* Visual Studio 2008 Professional installed (i.e. just Express Edition), so I can't test if x64 compilation works w/ VS Express at the moment.

Additionally, force a clean in our build.bat files before building, just whilst we're going through these build system updates.

And finally, add in the missing MACHINE=AMD64 option to our Tcl/Tk x64 build.

Tools/buildbot/build-amd64.bat

@@ -1,5 +1,6 @@
 @rem Used by the buildbot "compile" step.
 cmd /c Tools\buildbot\external-amd64.bat
-call "%VS90COMNTOOLS%vsvars32.bat"
+call "%VS90COMNTOOLS%\..\..\VC\vcvarsall.bat" x86_amd64
 REM cmd /q/c Tools\buildbot\kill_python.bat
+cmd /c Tools\buildbot\clean-amd64.bat
 vcbuild PCbuild\pcbuild.sln "Debug|x64"

Tools/buildbot/build.bat

@@ -2,5 +2,6 @@
 cmd /c Tools\buildbot\external.bat
 call "%VS90COMNTOOLS%vsvars32.bat"
 cmd /q/c Tools\buildbot\kill_python.bat
+cmd /c Tools\buildbot\clean.bat
 vcbuild /useenv PCbuild\pcbuild.sln "Debug|Win32"
 

Tools/buildbot/clean-amd64.bat

@@ -1,5 +1,5 @@
 @rem Used by the buildbot "clean" step.
-call "%VS90COMNTOOLS%vsvars32.bat"
+call "%VS90COMNTOOLS%\..\..\VC\vcvarsall.bat" x86_amd64
 cd PCbuild
 @echo Deleting .pyc/.pyo files ...
 del /s Lib\*.pyc Lib\*.pyo

Tools/buildbot/external-amd64.bat

@@ -2,16 +2,16 @@
 
 @rem Assume we start inside the Python source directory
 call "Tools\buildbot\external-common.bat"
-call "%VS90COMNTOOLS%\vsvars32.bat"
+call "%VS90COMNTOOLS%\..\..\VC\vcvarsall.bat" x86_amd64
 
 if not exist tcltk64\bin\tcl84g.dll (
     cd tcl-8.4.18.2\win
-    nmake -f makefile.vc COMPILERFLAGS=-DWINVER=0x0500 DEBUG=1 INSTALLDIR=..\..\tcltk64 clean all install
+    nmake -f makefile.vc COMPILERFLAGS=-DWINVER=0x0500 DEBUG=1 MACHINE=AMD64 INSTALLDIR=..\..\tcltk64 clean all install
     cd ..\..
 )
 
 if not exist tcltk64\bin\tk84g.dll (
     cd tk-8.4.18.1\win    
-    nmake -f makefile.vc COMPILERFLAGS=-DWINVER=0x0500 DEBUG=1 INSTALLDIR=..\..\tcltk64 TCLDIR=..\..\tcl-8.4.18.2 clean all install
+    nmake -f makefile.vc COMPILERFLAGS=-DWINVER=0x0500 DEBUG=1 MACHINE=AMD64 INSTALLDIR=..\..\tcltk64 TCLDIR=..\..\tcl-8.4.18.2 clean all install
     cd ..\..
 )

Tools/buildbot/external-common.bat

@@ -2,19 +2,20 @@
 @rem fetching external components into the root\.. buildbot directories.
 
 cd ..
-@rem XXX: Force the buildbots to start from a fresh environment.  Will be removed.
-if exist bzip2-1.0.3 rd /s/q bzip2-1.0.3
-if exist tcltk rd /s/q tcltk
-if exist tcltk64 rd /s/q tcltk64
-if exist tcl8.4.12 rd /s/q tcl8.4.12
-if exist tcl8.4.16 rd /s/q tcl8.4.16
-if exist tcl-8.4.18.1 rd /s/q tcl-8.4.18.1
-if exist tk8.4.12 rd /s/q tk8.4.12
-if exist tk8.4.16 rd /s/q tk8.4.16
-if exist tk-8.4.18.1 rd /s/q tk-8.4.18.1
-if exist db-4.4.20 rd /s/q db-4.4.20
-if exist openssl-0.9.8g rd /s/q openssl-0.9.8g
-if exist sqlite-source-3.3.4 rd /s/q sqlite-source-3.3.4    
+@rem XXX: If you need to force the buildbots to start from a fresh environment, uncomment
+@rem the following, check it in, then check it out, comment it out, then check it back in.
+@rem if exist bzip2-1.0.3 rd /s/q bzip2-1.0.3
+@rem if exist tcltk rd /s/q tcltk
+@rem if exist tcltk64 rd /s/q tcltk64
+@rem if exist tcl8.4.12 rd /s/q tcl8.4.12
+@rem if exist tcl8.4.16 rd /s/q tcl8.4.16
+@rem if exist tcl-8.4.18.1 rd /s/q tcl-8.4.18.1
+@rem if exist tk8.4.12 rd /s/q tk8.4.12
+@rem if exist tk8.4.16 rd /s/q tk8.4.16
+@rem if exist tk-8.4.18.1 rd /s/q tk-8.4.18.1
+@rem if exist db-4.4.20 rd /s/q db-4.4.20
+@rem if exist openssl-0.9.8g rd /s/q openssl-0.9.8g
+@rem if exist sqlite-source-3.3.4 rd /s/q sqlite-source-3.3.4    
 
 @rem bzip
 if not exist bzip2-1.0.3 svn export http://svn.python.org/projects/external/bzip2-1.0.3