TBB_IMPORTED_TARGETS is empty

[themightyoarfish]

tbb/cmake/templates/TBBConfig.cmake.in

Line 17 in 141b0e3

# TBB_IMPORTED_TARGETS

The CMake config alleges that this variable should include everything needed to target_link_libraries() to TBB. But it's empty.

I'm trying to find_package(TBB REQUIRED). It works if I link to TBB::tbb directly. Passing COMPONENTS tbb to the call does not change the behaviour. TBB is installed via this repo to /usr/local.
Is it a bug in the CMake config?