It is a bit difficult to tell the true reason for the build error, since I can only see a small part of it. However, this is what I found when I tried to build the solution to exercise 2:
I got a warning about the path length:
CMake Warning in C:/ncs/v2.6.0/nrf/subsys/nrf_security/src/CMakeLists.txt:
The object file directory
C:/ncs/v2.6.0/nrf/samples/devacademy/ncs-inter/lesson1/inter_less1_exer2_solution/build/tfm/secure_fw/partitions/crypto/mbedcrypto/nrf_security_src/CMakeFiles/crypto_service_mbedcrypto.dir/./
has 191 characters. The maximum full path to an object file is 250
characters (see CMAKE_OBJECT_PATH_MAX). Object file
C_/ncs/v2.6.0/nrf/ext/oberon/psa/core/library/psa_crypto_slot_management.o
cannot be safely placed under this directory. The build may not work
correctly.
To fix that error I renamed the application directory from inter_less1_exer2_solution to inter_less1_exer2_sol. This change resulted in a successful build.
Are you able to build successfully if you shorten the application name?
If not, please share the full build log by including it in a reply with Insert -> Code. Then we can help you to find a solution for your build error.
