[CMake] ExternalProject not being configured / custom_command not executed

[Bill Hoffman]

On 1/21/2016 2:33 PM, Kügler, David wrote:
> Hello everybody,
>
> I am trying to build a Project (via ExternalProject from a parent project).
>
> More precisely, I want to build the plus Toolkit (plustoolkit.org) and
> the subprojects using the build “superproject” (i.e. PlusBuild).
>
> It partly seems to work fine, but the ExternalProject PlusApp never
> actually gets built. Build-rule-files in the CMakeFiles folder are
> created, but it seems, the “configure”-command is never actually called.
> Thusly there is never ANY file created in the BINARY_DIR of the
> PlusApp-project subfolder.
>
> Why do I ask you guys, and not the people from Plus? Because a second
> subproject (i.e. PlusLib) just works fine, AND if I go ahead and extract
> the configure-command (i.e. the command-line-command) either from
> –trace-expand or from the PlusApp-CfgCmd.txt file (replacing ‘;’ with ‘“
> “’ (space and double quotation) ) it works fine.
>
> So: The command to configure, and the rule-files are created from CMake,
> but the command is actually not executed and I cannot say why.
>
> This definitely seems to be a hiccup in CMake, but I am at a deadend.
>
> Any Idea, why this is so?
>
> Using CMake 3.4.10 ; Visual Studio 2013 x64 ; Windows 8.1 ; plustoolkit
>
> (I hope this would be the relevant information)
>
Still sounds like a question for the PlusApp guys.  It is possible that 
they have some error in their CMakeLists.txt files that prevents this 
from working.  CMake is pretty well tested and external project tests 
are all passing for that platform and version  of CMake.

-Bill