define GLFW_INCLUDE_NONE, so glfw knows we're using custom headers.

.clang-format

@@ -99,10 +99,6 @@ IncludeIsMainSourceRegex: ''
 IncludeIsMainRegex:       '([-_](test|unittest))?$'
 IncludeBlocks:      Regroup
 IncludeCategories:
-  - Regex:         '^<glad/gl\.h>'
-    Priority:      1
-    SortPriority:  0
-    CaseSensitive: true
   - Regex:         '^<.*\.h>'
     Priority:      2
     SortPriority:  0

Makefile

@@ -12,6 +12,7 @@ CMAKE   ?= cmake -G 'Unix Makefiles'
 CPPFLAGS ?=
 CFLAGS   ?= -O2 -Wall -Wextra -Wpedantic -Wno-pointer-arith
 LDFLAGS  ?= -flto
+CPPFLAGS += -DGLFW_INCLUDE_NONE
 CFLAGS   += -std=gnu99
 
 # add a few extra flags depending on whether