Basically what I need is an automated way to update the product version number in WiX (3.0 with Votive etc), and then get that version number into an Inno Setup \"bootstrapp
No need to pass anything! You can simply let the InnoSetup Preprocessor read the version info straight from the binary's version resource, e.g.:
#define AppName "My App"
#define SrcApp "MyApp.exe"
#define FileVerStr GetFileVersion(SrcApp)
#define StripBuild(str VerStr) Copy(VerStr, 1, RPos(".", VerStr)-1)
#define AppVerStr StripBuild(FileVerStr)
[Setup]
AppName={#AppName}
AppVersion={#AppVerStr}
AppVerName={#AppName} {#AppVerStr}
UninstallDisplayName={#AppName} {#AppVerStr}
VersionInfoVersion={#FileVerStr}
VersionInfoTextVersion={#AppVerStr}
OutputBaseFilename=MyApp-{#FileVerStr}-setup
Before version 5.4.1 (2011-02-09) ISPP was not included in the default InnoSetup package. You had to download the InnoSetup Quick Start Pack: http://www.jrsoftware.org/isdl.php#qsp (thanks @Gwyn, for the update)