Good idea. Here is Geany's and Ctags' `config.h` on my Windows system: https://gist.github.com/eht16/e15e74e5f7bffebdf5f4ada38077ea59
I used `./autogen.sh && ./configure && make` on MSYS2 instead of the `mk_mingw.mak`. https://github.com/universal-ctags/ctags/blob/master/docs/windows.rst maybe has two interesting pointers: - `--disable-external-sort is a recommended option for Windows builds.` I used this flag to create the `config.h` above - `If you want to build an iconv enabled version, you must specify WITH_ICONV=yes` this is from the section about `mk_mingw.mak`, the Autotools part automatically detects iconv and on my system CTags was built with iconv support; Geany's `config.h` is missing the `HAVE_ICONV` macro
Fun fact regarding your first question: Geany defines `WIN32` whereas Ctags does not :).
Unless you beat me in time by finding the cause, I'll give the two options above a try at the weekend.