Had to rename sfml to sfmlbackend because on Windows the filesystem is case insensitive so include <SFML/*> was accidentally including _my_ <sfml/config.hpp> file.

src/sfmlbackend/backend.cpp

@@ -1,7 +1,7 @@
-#include "sfml/backend.hpp"
-#include "sfml/shaders.hpp"
-#include "sfml/sound.hpp"
-#include "sfml/textures.hpp"
+#include "sfmlbackend/backend.hpp"
+#include "sfmlbackend/shaders.hpp"
+#include "sfmlbackend/sound.hpp"
+#include "sfmlbackend/textures.hpp"
 
 namespace sfml {
   guecs::SpriteTexture Backend::texture_get(const string& name) {

src/sfmlbackend/components.cpp

@@ -1,5 +1,5 @@
 #include "guecs.hpp"
-#include "sfml/backend.hpp"
+#include "sfmlbackend/backend.hpp"
 
 namespace guecs {
   static Backend* BACKEND = nullptr;

src/sfmlbackend/config.cpp

@@ -1,4 +1,4 @@
-#include "sfml/config.hpp"
+#include "sfmlbackend/config.hpp"
 #include "dbc.hpp"
 #include <fmt/core.h>
 

src/sfmlbackend/shaders.cpp

@@ -1,8 +1,8 @@
-#include "sfml/shaders.hpp"
+#include "sfmlbackend/shaders.hpp"
 #include <SFML/Graphics/Image.hpp>
 #include "dbc.hpp"
 #include <fmt/core.h>
-#include "sfml/config.hpp"
+#include "sfmlbackend/config.hpp"
 #include <memory>
 
 namespace shaders {

src/sfmlbackend/sound.cpp

@@ -1,7 +1,7 @@
-#include "sfml/sound.hpp"
+#include "sfmlbackend/sound.hpp"
 #include "dbc.hpp"
 #include <fmt/core.h>
-#include "sfml/config.hpp"
+#include "sfmlbackend/config.hpp"
 
 namespace sound {
   static SoundManager SMGR;

src/sfmlbackend/textures.cpp

@@ -1,8 +1,8 @@
-#include "sfml/textures.hpp"
+#include "sfmlbackend/textures.hpp"
 #include <SFML/Graphics/Image.hpp>
 #include "dbc.hpp"
 #include <fmt/core.h>
-#include "sfml/config.hpp"
+#include "sfmlbackend/config.hpp"
 #include <memory>
 
 namespace textures {