Target TSID links to target "OsqpEigen::OsqpEigen" but target is not found in v2021.01.0

[traversaro]

Users that compiled the superbuild with make -j20 experienced this problem.

[traversaro]

Basically, the error was:

CMake Error at cmake/AddBipedalLocomotionLibrary.cmake:67 (add_library):
  Target "TSID" links to target "OsqpEigen::OsqpEigen" but the target was not
  found.  Perhaps a find_package() call is missing for an IMPORTED target, or
  an ALIAS target is missing?
Call Stack (most recent call first):
  src/TSID/CMakeLists.txt:9 (add_bipedal_locomotion_library)


CMake Error at cmake/AddBipedalLocomotionLibrary.cmake:67 (add_library):
  Target "TSID" links to target "OsqpEigen::OsqpEigen" but the target was not
  found.  Perhaps a find_package() call is missing for an IMPORTED target, or
  an ALIAS target is missing?
Call Stack (most recent call first):
  src/TSID/CMakeLists.txt:9 (add_bipedal_locomotion_library)

-- Generating done
CMake Generate step failed.  Build files cannot be regenerated correctly.
make[2]: *** [CMakeFiles/bipedal-locomotion-framework.dir/build.make:111: src/bipedal-locomotion-framework/CMakeFiles/YCMStamp/bipedal-locomotion-framework-configure] Error 1
make[1]: *** [CMakeFiles/Makefile2:1602: CMakeFiles/bipedal-locomotion-framework.dir/all] Error 2
make: *** [Makefile:95: all] Error 2

What happened is that blf was first configured when OsqpEigen was not compiled, and so FRAMEWORK_USE_OsqpEigen was initialized to OFF. Further configuration of blf with OsqpEigen installed did not changed the value of this variable, so the only way to fix the system was either to set it manually or to re-install the superbuild.