The arm/syscallent.h file is missing from 4.5.12, although this file has been in CVS for a while. This causes strace to run incorrectly on arm.
Fixed in cdb247397a416d02fbd8bd5fe6f9b9fac8b9610e.
Fixed in cdb247397a416d02fbd8bd5fe6f9b9fac8b9610e.