[date] link/build failure

[acgetchell]

Host Environment

• OS: Windows, Linux, macOS
• Compiler: clang-7, gcc-9, AppleClang 11.0.0 (clang-1100.0.33.8)

To Reproduce
Steps to reproduce the behavior:
./vcpkg install date

Add appropriate entries in CMakeLists, e.g.

acgetchell/CDT-plusplus@170f7c3

Failure logs

Windows:
https://ci.appveyor.com/project/acgetchell/cdt-plusplus/builds/29066845#L1214

Linux:
https://travis-ci.org/acgetchell/CDT-plusplus/jobs/615883747#L3777

macOS:

╭─adam@hapkido ~/CDT-plusplus/tools ‹feature/date› 
╰─$ ./build.sh 
-- The CXX compiler identification is AppleClang 11.0.0.11000033
-- Check for working CXX compiler: /Library/Developer/CommandLineTools/usr/bin/c++
-- Check for working CXX compiler: /Library/Developer/CommandLineTools/usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found Boost: /Users/adam/vcpkg/installed/x64-osx/include (found version "1.71.0")  
-- Using header-only CGAL
-- Targetting Unix Makefiles
-- Using /Library/Developer/CommandLineTools/usr/bin/c++ compiler.
-- DARWIN_VERSION=19
-- Mac Leopard detected
-- Found GMP: /Users/adam/vcpkg/installed/x64-osx/debug/lib/libgmp.a  
-- Found MPFR: /Users/adam/vcpkg/installed/x64-osx/debug/lib/libmpfr.a  
-- Found Boost: /Users/adam/vcpkg/installed/x64-osx/include (found suitable version "1.71.0", minimum required is "1.48")  
-- Boost include dirs: /Users/adam/vcpkg/installed/x64-osx/include
-- Boost libraries:    
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/adam/CDT-plusplus/build
Scanning dependencies of target initialize
[  6%] Building CXX object CMakeFiles/initialize.dir/src/initialize.cpp.o
[ 13%] Linking CXX executable initialize
[ 13%] Built target initialize
Scanning dependencies of target CDT_test
[ 20%] Building CXX object tests/CMakeFiles/CDT_test.dir/main.cpp.o
[ 26%] Building CXX object tests/CMakeFiles/CDT_test.dir/Ergodic_moves_3_test.cpp.o
[ 33%] Building CXX object tests/CMakeFiles/CDT_test.dir/Foliated_triangulation_test.cpp.o
[ 40%] Building CXX object tests/CMakeFiles/CDT_test.dir/Geometry_test.cpp.o
[ 46%] Building CXX object tests/CMakeFiles/CDT_test.dir/Manifold_test.cpp.o
[ 53%] Building CXX object tests/CMakeFiles/CDT_test.dir/Move_command_test.cpp.o
[ 60%] Building CXX object tests/CMakeFiles/CDT_test.dir/S3ActionTest.cpp.o
[ 66%] Building CXX object tests/CMakeFiles/CDT_test.dir/SphereTest.cpp.o
[ 73%] Building CXX object tests/CMakeFiles/CDT_test.dir/Tetrahedron_test.cpp.o
[ 80%] Building CXX object tests/CMakeFiles/CDT_test.dir/Torus_test.cpp.o
[ 86%] Building CXX object tests/CMakeFiles/CDT_test.dir/Utilities_test.cpp.o
[ 93%] Building CXX object tests/CMakeFiles/CDT_test.dir/VertexTest.cpp.o
[100%] Linking CXX executable CDT_test
Undefined symbols for architecture x86_64:
  "date::current_zone()", referenced from:
      currentDateTime() in Utilities_test.cpp.o
  "date::time_zone::get_info_impl(std::__1::chrono::time_point<std::__1::chrono::system_clock, std::__1::chrono::duration<long long, std::__1::ratio<1l, 1l> > >) const", referenced from:
      date::sys_info date::time_zone::get_info<std::__1::chrono::duration<long long, std::__1::ratio<1l, 1000000l> > >(std::__1::chrono::time_point<std::__1::chrono::system_clock, std::__1::chrono::duration<long long, std::__1::ratio<1l, 1000000l> > >) const in Utilities_test.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [tests/CDT_test] Error 1
make[1]: *** [tests/CMakeFiles/CDT_test.dir/all] Error 2
make: *** [all] Error 2

Additional context
#9006

[acgetchell]

Adding date::tz to target_link_libraries as suggested by the install yields:

"/Users/adam/Library/Application Support/JetBrains/Toolbox/apps/CLion/ch-0/192.7142.39/CLion.app/Contents/bin/cmake/mac/bin/cmake" -DCMAKE_BUILD_TYPE=Release -DCMAKE_TOOLCHAIN_FILE=/Users/adam/vcpkg/scripts/buildsystems/vcpkg.cmake -G "CodeBlocks - Unix Makefiles" /Users/adam/CDT-plusplus
-- Found Boost: /Users/adam/vcpkg/installed/x64-osx/include (found version "1.71.0")  
-- Using header-only CGAL
-- Targetting Unix Makefiles
-- Using /Library/Developer/CommandLineTools/usr/bin/c++ compiler.
-- DARWIN_VERSION=19
-- Mac Leopard detected
-- Found Boost: /Users/adam/vcpkg/installed/x64-osx/include (found suitable version "1.71.0", minimum required is "1.48")  
-- Boost include dirs: /Users/adam/vcpkg/installed/x64-osx/include
-- Boost libraries:    
-- Configuring done
CMake Error at /Users/adam/vcpkg/scripts/buildsystems/vcpkg.cmake:166 (_add_executable):
  Target "initialize" links to target "Threads::Threads" but the target was
  not found.  Perhaps a find_package() call is missing for an IMPORTED
  target, or an ALIAS target is missing?
Call Stack (most recent call first):
  CMakeLists.txt:137 (add_executable)

[Neumann-A]

please open up an upstream issue (https:/HowardHinnant/date). Target data::tz is linking to Threads::Threads and missing the find_dependency call for Threads since date only install the CMake generated config files which never perform such calls.

[acgetchell]

HowardHinnant/date#514

[acgetchell]

Upstream has fixed the issue via HowardHinnant/date@fc4cf09

Need port upgrade.