Build fails under MinGW
Currently Vala fails to build under MinGW with the following error (this is a very common issue from what I understand):
/bin/sh ../libtool --tag=CC --mode=link gcc -g -O2 -avoid-version -o libvalaccodegen.la -rpath /mingw64/lib/vala-0.46 valaccode.lo valaccodearraymodule.lo valaccodeassignmentmodule.lo valaccodeattribute.lo valaccodebasemodule.lo valaccodecompiler.lo valaccodecontrolflowmodule.lo valaccodedelegatemodule.lo valaccodememberaccessmodule.lo valaccodemethodcallmodule.lo valaccodemethodmodule.lo valaccodestructmodule.lo valaclassregisterfunction.lo valactype.lo valaenumregisterfunction.lo valagasyncmodule.lo valagdbusclientmodule.lo valagdbusmodule.lo valagdbusservermodule.lo valagerrormodule.lo valagirwriter.lo valagobjectmodule.lo valagtkmodule.lo valagsignalmodule.lo valagtypemodule.lo valagvariantmodule.lo valainterfaceregisterfunction.lo valastructregisterfunction.lo valatyperegisterfunction.lo -LD:/msys64/mingw64/lib -lgobject-2.0 -lintl -lglib-2.0 ../vala/libvala-0.46.la ../ccode/libvalaccode.la
libtool: error: can't build x86_64-w64-mingw32 shared library unless -no-undefined is specified
Adding the suggested '-no-undefined' solves it and I have not noticed any particular side effect (but I am still a beginner...).
Note: '-no-undefined' is already used by libvala
for the same reason (e98b0cdf).
I have pushed a fix on a fork (philippejer/vala@18259482), I can open a merge request if you like...