How can I install my own copy of Indy10 from source, in Delphi XE4, if I get "not a valid win32 application" error?

Question

Using the latest Indy10 sources from subversion, installing in to Delphi XE4, I get this error when I try to install "dclIndyProtocols180.bpl":

Error: 
Can't load package C:\dev\..\comp\Indy10\Lib\Output\BPI\Win32\Debug\dclIndyProtocols180.bpl.
%1 is not a valid Win32 application.

The BPI\Win32\Debug folder in question contains these files:

dclIndyCore180.bpl
dclIndyProtocols180.bpl
IndyCore180.bpi
IndyCore180.bpl
IndyProtocols180.bpi
IndyProtocols180.bpl
IndySystem180.bpi
IndySystem180.bpl

How do I fix or work around this? I am not exactly new to Indy, or Delphi, but each time there's a new delphi release, there are interesting surprises for those of us who prefer to build from source code and track subversion rather than using that random point in time which ships with the Delphi XE4 installer.

As a general side question: Is there any place where the status of the Indy project's subversion code, compared with whatever Embarcadero ships in their products is noted, or recorded?

Answer 1

By default a new package in Delphi might automatically be 64 bit, or you may have built a dependency as a 64 bit BPL, but not have switched to 32 bit for that BPL and rebuilt it.

Also you might have folders in your Library path that allow 32 bit and 64 bit BPls to try to load each other, causing this issue.