Make check fails on target test_installed_embed

I am on Ubuntu 19.04:

$ git clone git@github.com:pybind/pybind11.git
$ cd pybind11
$ mkdir build
$ cd build
$ cmake ..
-- The CXX compiler identification is GNU 8.3.0
-- Check for working CXX compiler: /bin/c++
-- Check for working CXX compiler: /bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found PythonInterp: /home/hakon/.pyenv/shims/python3.7 (found version "3.7.1") 
-- Found PythonLibs: /home/hakon/.pyenv/versions/3.7.1/lib/libpython3.7m.a
-- Performing Test HAS_CPP14_FLAG
-- Performing Test HAS_CPP14_FLAG - Success
-- Setting tests build type to MinSizeRel as none was specified
-- Building tests WITHOUT Eigen
-- Boost version: 1.67.0
-- Performing Test HAS_FLTO
-- Performing Test HAS_FLTO - Success
-- LTO enabled
-- Catch not detected. Interpreter tests will be skipped. Install Catch headers manually or use `cmake -DDOWNLOAD_CATCH=1` to fetch them automatically.
-- pybind11 v2.3.dev1
-- Configuring done
-- Generating done
-- Build files have been written to: /home/hakon/pybind11/build
hakon@hakon-Precision-7530:~/pybind11/build$ make check
Scanning dependencies of target mock_install
-- Install configuration: "MinSizeRel"
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/attr.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/buffer_info.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/pybind11.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/options.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/cast.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/operators.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/stl_bind.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/embed.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/detail
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/detail/descr.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/detail/init.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/detail/internals.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/detail/typeid.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/detail/class.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/detail/common.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/pytypes.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/eval.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/iostream.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/numpy.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/common.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/chrono.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/stl.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/complex.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/functional.h
-- Installing: /home/hakon/pybind11/build/mock_install/include/pybind11/eigen.h
-- Installing: /home/hakon/pybind11/build/mock_install/share/cmake/pybind11/pybind11Config.cmake
-- Installing: /home/hakon/pybind11/build/mock_install/share/cmake/pybind11/pybind11ConfigVersion.cmake
-- Installing: /home/hakon/pybind11/build/mock_install/share/cmake/pybind11/FindPythonLibsNew.cmake
-- Installing: /home/hakon/pybind11/build/mock_install/share/cmake/pybind11/pybind11Tools.cmake
-- Installing: /home/hakon/pybind11/build/mock_install/share/cmake/pybind11/pybind11Targets.cmake
[  0%] Built target mock_install
Scanning dependencies of target test_installed_embed
make[3]: *** [tests/test_cmake_build/CMakeFiles/test_installed_embed.dir/build.make:57: tests/test_cmake_build/CMakeFiles/test_installed_embed] Error 1
make[2]: *** [CMakeFiles/Makefile2:552: tests/test_cmake_build/CMakeFiles/test_installed_embed.dir/all] Error 2
make[1]: *** [CMakeFiles/Makefile2:255: tests/CMakeFiles/check.dir/rule] Error 2
make: *** [Makefile:216: check] Error 2

Any idea what might be the problem?

Start by reproducing the failure with cmake .. followed by make check on Ubuntu, then inspect the generated tests/test_cmake_build/CMakeFiles/test_installed_embed.dir/build.make referenced in the error. Determine which command for test_installed_embed exits with status 1 and document or fix the build failure, verifying that make check completes successfully.