If ENABLE_ICU=AUTO and find_package(ICU) fails to find ICU installed it gives it logs the following:

-- The following ICU libraries were not found:
--   uc (required)
-- Failed to find all ICU components (missing: ICU_INCLUDE_DIR ICU_LIBRARY _ICU_REQUIRED_LIBS_FOUND) 

But no fatal error occurs because ICU is optional, and is only needed for SASLPrep. The log output suggests something went wrong when it really didn't. Instead, let's suppress this log output and print something like:

ICU not found, SASLPrep disabled for SCRAM-SHA-256 authentication