[cmake-developers] Question about ALIAS targets

[Stephen Kelly]

David Cole via cmake-developers wrote:

> Is there a good reason why this error must be an error?
> 
>     CMake Error at CMakeLists.txt:23 (add_library):
>       add_library cannot create ALIAS target "MyProj::gtest" because
>       target "OtherProj::googletest" is IMPORTED.
> 
> The line of code is:
> 
>     add_library(MyProj::gtest ALIAS OtherProj::googletest)
> 
> Why is there any restriction on ALIAS targets about what sorts of
> targets they may be aliases of?

They were introduced here:

 https://cmake.org/gitweb?p=cmake.git;a=commitdiff;h=370bf554151a1

Aside from the information there, other commits may have extended or tweaked 
the features/restrictions.


> After my find_package(OtherProj) call, which is a super build which
> defines lots of imported targets, I want the target to be named gtest
> to match its library name, but OtherProj has named it googletest.

Why isn't there a standard name? Should upstream provide the imported 
target? Has any effort been made to make upstream provide it? Is the name 
from OtherProj namespaced? Why do you need it to have a particular name? Why 
does OtherProj expose it? Should it expose that target for you to use (it 
seems an internal thing to me)?

Thanks,

Steve.