#615 GTK3V2MAIN: Windows build fails — gtk3lib and parts require GTK3 unconditionally

[Allen D Byrne]

app/wlib/CMakeLists.txt unconditionally adds gtk3lib which calls
find_package(GTK3 REQUIRED), failing on Windows where there is no GTK3.
The default branch correctly guards this with if(XTRKCAD_USE_GTK) and
routes to mswlib on Windows.

app/bin/parts/CMakeLists.txt also calls find_package(GTK3 REQUIRED)
unconditionally, and app/bin/CMakeLists.txt adds parts without a Windows
guard.

Fix: add if(NOT WIN32) guards to route wlib to mswlib on Windows and
skip the GTK3-dependent parts subdirectory until it is ported to Win32/mswlib.

Branch: bug-615-win-gtk3lib-parts

[Martin Fischer]

Duplicate: see bug #612

[Martin Fischer]

Windows + GTK3 build environment required, GTK3 wlib will replace mswlib on Windows

[Martin Fischer]

Closed after CI was changed to use MSYS-mingw GTK3 packages