The windows build of Firebird 3 is broken (note: I haven't checked the Firebird 4 build, might have the same problem).
It fails when building gpre_boot, this failure is introduced in: commit 40f782ae3e918c4f3842571ff8064be1c4f54961 Author: AlexPeshkoff <peshk...@mail.ru> Date: Fri Jan 13 14:29:54 2017 +0300 Backported fix for CORE-5452: Segfault when engine's dynamic library is unloaded right after closing worker threads (GC and/or cache writer) Not 100% sure, but the cause seems to be: ..\..\..\src\common\isc_sync.cpp(2151): error C2653: 'Thread': is not a class or namespace name ..\..\..\src\common\isc_sync.cpp(2151): error C3861: 'sleep': identifier not found Mark -- Mark Rotteveel ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel