Trying to configure CMake tool chain on Ubuntu - cmake

Question

The software will eventually run on an embedded Linux platform. To start, we wrote a library, with all C files in the same folder, and C++ files in a test folder under it.
MyLib
a.c
b.c
MyLib/test
test.cpp
This works on Windows 10, using CMake, Ninja and CLang plus doctest as a test framework. All of these tools are installed under vcpkg.
I am now trying to get everything configured and running on Ubuntu 16.04. All of the tools and source code have been retrieved from our repository. I have tried to build the library and test with Qt, cmake-gui and the command line without success.
Using CMake-gui, after browsing to the source and destination, clicking the Configure button causes the error
CMake Error: CMake was unable to find a build program corresponding to "Ninja".
CMAKE_MAKE_PROGRAM was not set.
The ninja program is in ~/../vcpkg/downloads/tools/ninja-1.8.2-linux/ folder.
I had different errors when trying to build from the command line.
Are there any examples of configurations that work with controlled tools instead of those in the environment?
Edit: added
CMakeLists.txt
cmake_minimum_required(VERSION 3.14)
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
project(PSOC_LIB)
option(BUILD_TESTS "bulid tests project" OFF)
set(psoc_lib_VERSION_MAJOR 0)
set(psoc_lib_VERSION_MINOR 1)
set(psoc_lib_VERSION_PATCH 0)
set(psoc_lib_VERSION "${psoc_lib_VERSION_MAJOR}.${psoc_lib_VERSION_MINOR}.${psoc_lib_VERSION_PATCH}")
set(PROJ_NAME "\"PSOC Library\"") # PROJECT_NAME is a predefined variable
set(PROJECT_DESCRIPTION "\"Crossplatform library for products\"")
configure_file(include/psoc/config.h.in
${CMAKE_BINARY_DIR}/include/psoc/config.h
)
set(SOURCES
# 5 *.c files
)
add_library(PSOC_LIB ${SOURCES})
target_include_directories(PSOC_LIB PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/include)
target_compile_definitions(PSOC_LIB PRIVATE _CRT_SECURE_NO_WARNINGS=1)
if (BUILD_TESTS)
include(CTest)
enable_testing()
add_subdirectory(test)
endif (BUILD_TESTS)
test/CmakeLists.txt
cmake_minimum_required(VERSION 3.10)
set(TEST_SOURCES
test.cpp
)
find_package(doctest CONFIG REQUIRED)
add_executable(test_runner test_runner.cpp ${TEST_SOURCES})
target_compile_definitions(test_runner PRIVATE _SILENCE_CXX17_ALLOCATOR_VOID_DEPRECATION_WARNING) #silence warnings about allocator<void> deprecation
target_compile_definitions(test_runner PRIVATE _WIN32_WINNT=0x0601) #target windows 7
target_link_libraries(test_runner PSOC_LIB doctest::doctest)
add_test(all_tests test_runner)
Under Windows, the files in the test folder are build even when BUILD_TESTS is OFF. Under Linux, the test and Testing folders are created only when BUILD_TESTS is ON.

Answer 1

I created a shell script that builds an executable test file.
#!/bin/bash
# Build a debug version of the PSOC_LIB and related tests
mkdir build
cd build
../../../vcpkg_pml/vcpkg/downloads/tools/cmake-3.14.0-linux/cmake-3.14.0-Linux-x86_64/bin/cmake -G Ninja -DCMAKE_BUILD_TYPE=Debug -S ../
ninja