ST platform building is broken. Found on commit: 66ee5c8861a9bbf95849ba1987e7e0b6c80bf5a4.
It was caused by 6242cf598819975ddb53a95b80412e498a6f34f5 - Platform: stm32l5xx: Add ARMCLANG and IAR support.
The GCC buildings are all failing, it's because of the change of the RTX library in the above patch:

-   set (RTX_LIB_PATH "${CMSIS_DIR}/RTOS2/RTX/Library/GCC/libRTX_V8MMN.a")
+   set(RTX_LIB_PATH "${CMSIS_DIR}/RTOS2/RTX/Library/GCC/RTX_V8MMN.a")

which I believe is done by mistake.
After the name was fixed, lots of configurations with "debug" build type still failed due to insufficient flash space.
Not sure "debug" type not supported is intentional or not.
IAR building was not checked.

Build summary:
STM_DISCO_L562QE/ARMCLANG/ConfigCoreIPC.cmake/Debug: False
STM_DISCO_L562QE/ARMCLANG/ConfigCoreIPC.cmake/Release: True
STM_DISCO_L562QE/ARMCLANG/ConfigCoreIPC.cmake/Relwithdebinfo: True
STM_DISCO_L562QE/ARMCLANG/ConfigCoreIPC.cmake/Minsizerel: True
STM_DISCO_L562QE/ARMCLANG/ConfigCoreIPCTfmLevel2.cmake/Debug: False
STM_DISCO_L562QE/ARMCLANG/ConfigCoreIPCTfmLevel2.cmake/Release: True
STM_DISCO_L562QE/ARMCLANG/ConfigCoreIPCTfmLevel2.cmake/Relwithdebinfo: True
STM_DISCO_L562QE/ARMCLANG/ConfigCoreIPCTfmLevel2.cmake/Minsizerel: True
STM_DISCO_L562QE/ARMCLANG/ConfigRegressionIPCTfmLevel2.cmake/Debug: False
STM_DISCO_L562QE/ARMCLANG/ConfigRegressionIPCTfmLevel2.cmake/Release: True
STM_DISCO_L562QE/ARMCLANG/ConfigRegressionIPCTfmLevel2.cmake/Relwithdebinfo: True
STM_DISCO_L562QE/ARMCLANG/ConfigRegressionIPCTfmLevel2.cmake/Minsizerel: True
STM_DISCO_L562QE/GNUARM/ConfigCoreIPC.cmake/Debug: True
STM_DISCO_L562QE/GNUARM/ConfigCoreIPC.cmake/Release: True
STM_DISCO_L562QE/GNUARM/ConfigCoreIPC.cmake/Relwithdebinfo: True
STM_DISCO_L562QE/GNUARM/ConfigCoreIPC.cmake/Minsizerel: True
STM_DISCO_L562QE/GNUARM/ConfigCoreIPCTfmLevel2.cmake/Debug: True
STM_DISCO_L562QE/GNUARM/ConfigCoreIPCTfmLevel2.cmake/Release: True
STM_DISCO_L562QE/GNUARM/ConfigCoreIPCTfmLevel2.cmake/Relwithdebinfo: True
STM_DISCO_L562QE/GNUARM/ConfigCoreIPCTfmLevel2.cmake/Minsizerel: True
STM_DISCO_L562QE/GNUARM/ConfigRegressionIPCTfmLevel2.cmake/Debug: True
STM_DISCO_L562QE/GNUARM/ConfigRegressionIPCTfmLevel2.cmake/Release: True
STM_DISCO_L562QE/GNUARM/ConfigRegressionIPCTfmLevel2.cmake/Relwithdebinfo: True
STM_DISCO_L562QE/GNUARM/ConfigRegressionIPCTfmLevel2.cmake/Minsizerel: True
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigCoreIPC.cmake/Debug: False
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigCoreIPC.cmake/Release: True
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigCoreIPC.cmake/Relwithdebinfo: True
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigCoreIPC.cmake/Minsizerel: True
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigCoreIPCTfmLevel2.cmake/Debug: False
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigCoreIPCTfmLevel2.cmake/Release: True
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigCoreIPCTfmLevel2.cmake/Relwithdebinfo: True
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigCoreIPCTfmLevel2.cmake/Minsizerel: True
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigRegressionIPCTfmLevel2.cmake/Debug: False
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigRegressionIPCTfmLevel2.cmake/Release: True
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigRegressionIPCTfmLevel2.cmake/Relwithdebinfo: True
STM_NUCLEO_L552ZE_Q/ARMCLANG/ConfigRegressionIPCTfmLevel2.cmake/Minsizerel: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigCoreIPC.cmake/Debug: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigCoreIPC.cmake/Release: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigCoreIPC.cmake/Relwithdebinfo: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigCoreIPC.cmake/Minsizerel: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigCoreIPCTfmLevel2.cmake/Debug: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigCoreIPCTfmLevel2.cmake/Release: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigCoreIPCTfmLevel2.cmake/Relwithdebinfo: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigCoreIPCTfmLevel2.cmake/Minsizerel: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigRegressionIPCTfmLevel2.cmake/Debug: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigRegressionIPCTfmLevel2.cmake/Release: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigRegressionIPCTfmLevel2.cmake/Relwithdebinfo: True
STM_NUCLEO_L552ZE_Q/GNUARM/ConfigRegressionIPCTfmLevel2.cmake/Minsizerel: True