Linux – Making CMake print commands before executing

cmakegnu-makelinux

I'm working on a large C++ project built with CMake on Linux. CMake runs okay, producing a horde of Makefiles in the tree of modules and applications. Running GNU make leads to linker errors. How can I get make to print out the exact commands before running them?

The -d option does not print the commands, but plenty of information that hasn't been helpful.

The -n option prints all the commands, but does not run them, so I can't tell were exactly the trouble is. Examining the stdout from make -n, I don't see any commands that are relevant. I suspect some commands change depending on the results of earlier commands, and the hierarchy of Makefiles makes it difficult to tell what's really going on.

I don't see any other options in make's man page that seem helpful.

Best Answer

I am fairly sure this will work:

make VERBOSE=1

You should also be able to add this to your CMakeLists.txt to permanently set that:

set(CMAKE_VERBOSE_MAKEFILE on)

This is covered in the CMake FAQ.

Related Solutions

Using CMake with GNU Make: How to see the exact commands

CMake 3.14+ you can simply specify the verbosity of the build tool.

# Configure your project
cmake -S . -B build/

# Build your project with verbose output
# This will allow you to see the exact commands being used.
# And this works with Makefiles, Ninja, Visual Studio, etc.
cmake --build build --verbose

Before CMake 3.14

When you run make, add VERBOSE=1 to see the full command output. For example:

cmake .
make VERBOSE=1

Or you can add -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON to the cmake command for permanent verbose command output from the generated Makefiles.

cmake -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON .
make

To reduce some possibly less-interesting output you might like to use the following options. The option CMAKE_RULE_MESSAGES=OFF removes lines like [ 33%] Building C object..., while --no-print-directory tells make to not print out the current directory filtering out lines like make[1]: Entering directory and make[1]: Leaving directory.

cmake -DCMAKE_RULE_MESSAGES:BOOL=OFF -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON .
make --no-print-directory

CMake equivalent of ‘configure –prefix=DIR && make all install ‘

You can pass in any CMake variable on the command line, or edit cached variables using ccmake/cmake-gui. On the command line,

cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr . && make all install

Would configure the project, build all targets and install to the /usr prefix. The type (PATH) is not strictly necessary, but would cause the Qt based cmake-gui to present the directory chooser dialog.

Some minor additions as comments make it clear that providing a simple equivalence is not enough for some. Best practice would be to use an external build directory, i.e. not the source directly. Also to use more generic CMake syntax abstracting the generator.

mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr .. && cmake --build . --target install --config Release

You can see it gets quite a bit longer, and isn't directly equivalent anymore, but is closer to best practices in a fairly concise form... The --config is only used by multi-configuration generators (i.e. MSVC), ignored by others.

Best Answer

Related Solutions

Using CMake with GNU Make: How to see the exact commands

CMake equivalent of ‘configure –prefix=DIR && make all install ‘

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