source/unit_threaded/light.d(50,15): Error: `@safe` function `unit_threaded.light.runTestsImpl` cannot call `@system` function `core.stdc.stdio.printf`
/opt/dmd-safe/dmd/generated/linux/release/64/../../../../../druntime/import/core/stdc/stdio.d(1251,9):        `core.stdc.stdio.printf` is declared here
source/unit_threaded/light.d(54,11): Error: `@safe` function `unit_threaded.light.runTestsImpl` cannot call `@system` function `core.stdc.stdio.printf`
/opt/dmd-safe/dmd/generated/linux/release/64/../../../../../druntime/import/core/stdc/stdio.d(1251,9):        `core.stdc.stdio.printf` is declared here
/opt/dmd-safe/dmd/dmd-safe failed with exit code 1.