YCM build failing with Xcode

[nunoguedelha]

Issue description

The YCM build is failing when building the superbuild on Macos using Xcode toolchain.

Steps to reproduce the issue:

• update the robotology-superbuild repo to the latest commit on master branch today,
• run cmake on an empty build folder (cmake ./ -G Xcode),
• set to ON the options:

ROBOTOLOGY_ENABLE_CORE
ROBOTOLOGY_ENABLE_DYNAMICS
ROBOTOLOGY_ENABLE_ICUB_HEAD
ROBOTOLOGY_USES_GAZEBO
ROBOTOLOGY_USES_MATLAB

(This configuration has been used for a long time on the single motor test setup, for starting a set of EMS+2FOC boards driving a single iCub motor).

• a few repos are set with YCM_EP_DEVEL_MODE ON.
• But the following devel mode option is OFF:

YCM_EP_DEVEL_MODE_YCM

• run xcodebuild -target ALL_UPDATE,
• run xcodebuild -target ALL_BUILD.

The last commands fails.

Failure log

...
PhaseScriptExecution CMake\ Rules build/robotology-superbuild.build/Debug/YCM.build/Script-5053C3E3F7E142C7BBCF2381.sh
    cd /Users/nunoguedelha/dev/robotology-superbuild
    /bin/sh -c /Users/nunoguedelha/dev/robotology-superbuild/build/robotology-superbuild.build/Debug/YCM.build/Script-5053C3E3F7E142C7BBCF2381.sh
echo "Skipping update step for 'YCM'"
Skipping update step for 'YCM'
cd /Users/nunoguedelha/dev/robotology-superbuild/robotology/YCM && /usr/local/Cellar/cmake/3.15.3/bin/cmake -E echo_append
echo "No patch step for 'YCM'"
No patch step for 'YCM'
/usr/local/Cellar/cmake/3.15.3/bin/cmake -E echo_append
/usr/local/Cellar/cmake/3.15.3/bin/cmake -E touch /Users/nunoguedelha/dev/robotology-superbuild/build/robotology/YCM/CMakeFiles/YCMStamp/Debug/YCM-patch
echo "Performing configure step for 'YCM'"
Performing configure step for 'YCM'
cd /Users/nunoguedelha/dev/robotology-superbuild/build/robotology/YCM && /usr/local/Cellar/cmake/3.15.3/bin/cmake --no-warn-unused-cli -DCMAKE_PREFIX_PATH:PATH=/Users/nunoguedelha/dev/robotology-superbuild/build/install -C/Users/nunoguedelha/dev/robotology-superbuild/build/robotology/YCM/CMakeFiles/YCMTmp/YCM-cache-Debug.cmake -GXcode /Users/nunoguedelha/dev/robotology-superbuild/robotology/YCM
Not searching for unused variables given on the command line.
loading initial cache file /Users/nunoguedelha/dev/robotology-superbuild/build/robotology/YCM/CMakeFiles/YCMTmp/YCM-cache-Debug.cmake
CMake Error: Error: generator : Xcode
Does not match the generator used previously: Unix Makefiles
Either remove the CMakeCache.txt file and CMakeFiles directory or choose a different binary directory.
make: *** [/Users/nunoguedelha/dev/robotology-superbuild/build/robotology/YCM/CMakeFiles/YCMStamp/Debug/YCM-configure] Error 1
Command /bin/sh failed with exit code 2

** BUILD FAILED **

[nunoguedelha]

@drdanz gave a quick look and suspects the following: it seems that the YCM has been compiled a first time with the normal cmake tool, and a second time with the Xcode toolchain, which would result in the logged error.
Actually the superbuild downloads and compiles YCM at the bootstrap phase and then again when building all the other repos.

[nunoguedelha]

Indeed, a grep -Rs "CMAKE_GENERATOR:INTERNAL=" robotology/* in the main build folder gives:

robotology/BlockFactory/CMakeCache.txt:CMAKE_GENERATOR:INTERNAL=Xcode
robotology/ICUB/CMakeCache.txt:CMAKE_GENERATOR:INTERNAL=Xcode
robotology/RobotTestingFramework/CMakeCache.txt:CMAKE_GENERATOR:INTERNAL=Xcode
robotology/YARP/CMakeCache.txt:CMAKE_GENERATOR:INTERNAL=Xcode
robotology/YCM/CMakeCache.txt:CMAKE_GENERATOR:INTERNAL=Unix Makefiles
robotology/icub-firmware-shared/CMakeCache.txt:CMAKE_GENERATOR:INTERNAL=Xcode
robotology/icub-gazebo/CMakeCache.txt:CMAKE_GENERATOR:INTERNAL=Xcode
robotology/wholeBodyInterface/CMakeCache.txt:CMAKE_GENERATOR:INTERNAL=Xcode

Where the line robotology/YCM/CMakeCache.txt:CMAKE_GENERATOR:INTERNAL=Unix Makefiles shows that the YCM Cmake files had already been generated with the Unix Makefiles generator (by running cmake without the -G Xcode option).

[nunoguedelha]

Copying MacOSX users. Hope I didn't forget anyone...

CC @lrapetti @DanielePucci @kouroshD @claudia-lat

[traversaro]

Solving #267 should prevent this kind of issues from happening.

[traversaro]

I was able to reproduce this in #276 .

[traversaro]

As seen in #276 , the issue is reproducible also on Ubuntu when using a generator different from the default one, for example Ninja cc @diegoferigo . I opened a YCM issue in robotology/ycm-cmake-modules#290 .

I did not mentioned that before, but clearly a workaround is to use a normally installed YCM instead of bootstrapping it.

[diegoferigo]

I did not mentioned that before, but clearly a workaround is to use a normally installed YCM instead of bootstrapping it.

I use Ninja but my setup also has this configuration, probably this is the reason why this problem never occurred to me :)

[traversaro]

Hi @nunoguedelha , this will be fixed upstream in robotology/ycm-cmake-modules#294 , and I added a temporary workaround i for the robotology-superbuild in #276 , let me know if this solves your problems.

[traversaro]

As robotology/ycm-cmake-modules#290 is tracking the problem on YCM side, if the problem is solved for you @nunoguedelha feel free to close the issue, thanks!

[traversaro]

I close as this was fixed in #276 .