CMake Linux - don't get executable - linux

Question

I'm using CMake with Visual Studio 2019 to build an executable with the gcc compiler from a small C-program by using an Ubuntu in a Docker container. My problem is now, that I don't get an executable although I don't get any error during the building process.
A manual build on the command line with gcc -o CMakeExec CMakeExec.c works correct.
Here is my config:
CMakeExec.h
#pragma once
#include <stdio.h>
CMakeExec.c
#include "CMakeExec.h"
int main()
{
printf("This is a test!");
return 0;
}
First CMakeList.txt
cmake_minimum_required (VERSION 3.8)
add_executable (CMakeExec "CMakeExec.c" "CMakeExec.h")
Second CMakeList.txt
cmake_minimum_required (VERSION 3.8)
project ("CMakeExec")
add_subdirectory ("CMakeExec")
CMakeSettings.json
{
"name": "Linux-GCC-Debug",
"generator": "Ninja",
"configurationType": "Debug",
"cmakeExecutable": "cmake",
"remoteCopySourcesExclusionList": [ ".vs", ".git", "out" ],
"cmakeCommandArgs": "",
"buildCommandArgs": "",
"ctestCommandArgs": "",
"inheritEnvironments": [ "linux_x64" ],
"remoteMachineName": "-970746741;localhost (username=test, port=5000, authentication=Password)",
"remoteCMakeListsRoot": "$HOME/.vs/${projectDirName}/${workspaceHash}/src",
"remoteBuildRoot": "$HOME/.vs/${projectDirName}/${workspaceHash}/out/build/${name}",
"remoteInstallRoot": "$HOME/.vs/${projectDirName}/${workspaceHash}/out/install/${name}",
"remoteCopySources": true,
"rsyncCommandArgs": "-t --delete --delete-excluded",
"remoteCopyBuildOutput": false,
"remoteCopySourcesMethod": "rsync",
"addressSanitizerRuntimeFlags": "detect_leaks=0",
"variables": []
}
Dockerfile
# our local base image
FROM ubuntu
LABEL description="Container for use with Visual Studio"
# install build dependencies
RUN apt-get update && apt-get install -y g++ rsync zip openssh-server make
# configure SSH for communication with Visual Studio
RUN mkdir -p /var/run/sshd
RUN echo 'PasswordAuthentication yes' >> /etc/ssh/sshd_config && \
ssh-keygen -A
# expose port 22
EXPOSE 22
Output from the Visual Studio
Copying files to the remote machine.
Starting copying files to remote machine.
[rsync] rsync -t --delete --delete-excluded -v -r --exclude=.vs --exclude=.git --exclude=out -8 "." rsync://test#localhost:51754/-home-test-.vs-CMakeExec-369e0150-0280-45f1-b4c9-244852742d47-src
[rsync] sending incremental file list
[rsync] CMakeSettings.json
[rsync]
[rsync] sent 291 bytes received 54 bytes 690.00 bytes/sec
[rsync] total size is 2,765 speedup is 8.01
Finished copying files (elapsed time 00h:00m:02s:371ms).
CMake generation started for configuration: 'Linux-GCC-Debug'.
Found cmake executable at /usr/bin/cmake.
/usr/bin/cmake -G "Ninja" -DCMAKE_BUILD_TYPE:STRING="Debug" -DCMAKE_INSTALL_PREFIX:PATH="$HOME/.vs/CMakeExec/369e0150-0280-45f1-b4c9-244852742d47/out/install/Linux-GCC-Debug" "/home/test/.vs/CMakeExec/369e0150-0280-45f1-b4c9-244852742d47/src/CMakeLists.txt";
[CMake] -- Configuring done
[CMake] -- Generating done
[CMake] -- Build files have been written to: /home/test/.vs/CMakeExec/369e0150-0280-45f1-b4c9-244852742d47/out/build/Linux-GCC-Debug
Extracted CMake variables.
Extracted source files and headers.
Extracted code model.
Extracted includes paths.
CMake generation finished.
I hope that anyone has an idea what is missing.