On some build host systems the CMAKE_C_COMPILER variable contains a filename that has a .exe suffix. This needs to be cut off as well.
With the current version GNUARM_PREFIX results in arm-none-eabi.exe
The resulting error message:
/usr/bin/sh: CMAKE_GNUARM_AR-NOTFOUND: command not found make[5]: *** [library/CMakeFiles/mbedcrypto.dir/build.make:1089: library/mbedcrypto.a] Error 127 make[4]: *** [CMakeFiles/Makefile2:178: library/CMakeFiles/mbedcrypto.dir/all] Error 2 make[3]: *** [Makefile:130: all] Error 2