[Gecode] add builder

[odow]

An optional dependency of https://github.com/JuliaPackaging/Yggdrasil/pull/4866 that would be useful to include

[giordano]

Windows

[01:27:21] /opt/bin/x86_64-w64-mingw32-libgfortran3-cxx11/x86_64-w64-mingw32-g++ --sysroot=/opt/x86_64-w64-mingw32/x86_64-w64-mingw32/sys-root/  -std=c++11 -O3 -DNDEBUG -Wl,--whole-archive CMakeFiles/fzn-gecode.dir/objects.a -Wl,--no-whole-archive -o bin/fzn-gecode.exe -Wl,--out-implib,libfzn-gecode.dll.a -Wl,--major-image-version,0,--minor-image-version,0 @CMakeFiles/fzn-gecode.dir/linklibs.rsp
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text+0xce): undefined reference to `__imp_closesocket'
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text$_ZN6Gecode10CPProfiler9Connector14sendOverSocketEv[_ZN6Gecode10CPProfiler9Connector14sendOverSocketEv]+0x17f): undefined reference to `__imp_send'
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text$_ZN6Gecode10CPProfiler9Connector7connectEv[_ZN6Gecode10CPProfiler9Connector7connectEv]+0x1f): undefined reference to `__imp_WSAStartup'
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text$_ZN6Gecode10CPProfiler9Connector7connectEv[_ZN6Gecode10CPProfiler9Connector7connectEv]+0x86): undefined reference to `__imp_getaddrinfo'
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text$_ZN6Gecode10CPProfiler9Connector7connectEv[_ZN6Gecode10CPProfiler9Connector7connectEv]+0xaf): undefined reference to `__imp_socket'
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text$_ZN6Gecode10CPProfiler9Connector7connectEv[_ZN6Gecode10CPProfiler9Connector7connectEv]+0xbb): undefined reference to `__imp_connect'
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text$_ZN6Gecode10CPProfiler9Connector7connectEv[_ZN6Gecode10CPProfiler9Connector7connectEv]+0xc2): undefined reference to `__imp_closesocket'
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text$_ZN6Gecode10CPProfiler9Connector7connectEv[_ZN6Gecode10CPProfiler9Connector7connectEv]+0x128): undefined reference to `__imp_freeaddrinfo'
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text$_ZN6Gecode10CPProfiler9Connector7connectEv[_ZN6Gecode10CPProfiler9Connector7connectEv]+0x144): undefined reference to `gai_strerrorA'
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text$_ZN6Gecode10CPProfiler9Connector5startERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEib[_ZN6Gecode10CPProfiler9Connector5startERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEib]+0xb32): undefined reference to `__imp_send'
[01:27:23] libgecodesearch.a(tracer.cpp.obj):tracer.cpp:(.text$_ZN6Gecode10CPProfiler9Connector7restartEi[_ZN6Gecode10CPProfiler9Connector7restartEi]+0x7da): undefined reference to `__imp_send'

is probably missing linking to libws2_32 (-lws2_32).

macOS:

[01:27:04] In file included from /workspace/srcdir/gecode/gecode/set/cardinality.cpp:39:
[01:27:04] In file included from /workspace/srcdir/gecode/gecode/set/int.hh:296:
[01:27:04] /workspace/srcdir/gecode/gecode/set/int/weights.hpp:127:14: error: no viable overloaded '='
[01:27:04]     elements = elements0; weights = weights0;
[01:27:04]     ~~~~~~~~ ^ ~~~~~~~~~
[01:27:04] /workspace/srcdir/gecode/gecode/kernel/data/shared-array.hpp:53:9: note: candidate function (the implicit copy assignment operator) not viable: 'this' argument has type 'const SharedArray<int>', but method is not marked const
[01:27:04]   class SharedArray : public SharedHandle {
[01:27:04]         ^
[01:27:04] In file included from /workspace/srcdir/gecode/gecode/set/cardinality.cpp:39:
[01:27:04] In file included from /workspace/srcdir/gecode/gecode/set/int.hh:296:
[01:27:04] /workspace/srcdir/gecode/gecode/set/int/weights.hpp:127:35: error: no viable overloaded '='
[01:27:04]     elements = elements0; weights = weights0;
[01:27:04]                           ~~~~~~~ ^ ~~~~~~~~

I haven't read the code but it sounds like a genuine bug, maybe not caught by GCC. FreeBSD has similar errors, and more.