ERROR: No commands were logged to the build logs

[pbesedm]

I have compiled clang-6.0.0 on my centos7 system, and this is the log of config_gen.py:

$ ~/.vim/bundle/YCM-Generator/config_gen.py --verbose .
Preparing build directory...
$ make clean
rm -f hello main.o

Running make...
$ make -i -j2
clang -o hello main.c
Build completed in 0.05 sec

Collected 0 relevant entries for C compilation (0 discarded).
Collected 0 relevant entries for C++ compilation (0 discarded).

ERROR: No commands were logged to the build logs (C: /tmp/tmpSHe_Am, C++: /tmp/tmp4YNpNk).
Your build system may not be compatible.

The project is just an simple "helloworld" example, and the Makefile is:

all:
	$(CC) -o hello main.c
clean:
	rm -f hello main.o

What else do i need to provide?

[cposture]

I also occur this problem, the log of config_gen.py:

Collected 0 relevant entries for C compilation (0 discarded).
Collected 0 relevant entries for C++ compilation (0 discarded).

ERROR: No commands were logged to the build logs (C: /tmp/tmpQU_y38, C++: /tmp/tmpS8d1X7).
Your build system may not be compatible.

I compile my project with makefile in the root of project, and execute config_gen.py successfully but any log is empty.

To collect log of make command, I fix it simply, so not compatible for others（C++, make）:
code before change:

    FNULL = open(os.devnull, "w")
    proc_opts = {} if verbose else {
        "stdin": FNULL,
        "stdout": FNULL,
        "stderr": FNULL
    }

code after change:

      f_build_log_path = open(cxx_build_log_path, "w")
      proc_opts = {} if verbose else {
         "stdin" : FNULL,
         "stdout": f_build_log_path,
         "stderr": FNULL
      }

after fix, don't use --verbose option, successfully, the log:

Preparing build directory...
$ make clean

Running make...
$ make -i -j4
Build completed in 14.73 sec

Collected 0 relevant entries for C compilation (0 discarded).
Collected 132 relevant entries for C++ compilation (0 discarded).
Created YCM config file with 33 C++ flags