Yesterday I started getting a build fail with the following error. I am on FreeBSD using clang v7.0.1
[ 41%] Building C object source/blender/makesdna/intern/CMakeFiles/bf_dna.dir/dna_verify.c.o
<<blend_dir>>/umfbuild/source/blender/makesdna/intern/dna_verify.c:147:1: error: redefinition of enumerator 'assert_line_147'
BLI_STATIC_ASSERT(sizeof(struct IDOverrideStaticPropertyOperation) == 48, "DNA struct size verify");
^
<<blend_dir>>/blender/source/blender/blenlib/BLI_assert.h:106:12: note: expanded from macro 'BLI_STATIC_ASSERT'
enum { _BLI_ASSERT_CONCAT(assert_line_, __LINE__) = 1 / (int)(!!(a)) };
^
<<blend_dir>>/blender/source/blender/blenlib/BLI_assert.h:99:36: note: expanded from macro '_BLI_ASSERT_CONCAT'
# define _BLI_ASSERT_CONCAT(a, b) _BLI_ASSERT_CONCAT_(a, b)
^
<<blend_dir>>/blender/source/blender/blenlib/BLI_assert.h:98:37: note: expanded from macro '_BLI_ASSERT_CONCAT_'
# define _BLI_ASSERT_CONCAT_(a, b) a##b
^
<scratch space>:147:1: note: expanded from here
assert_line_147
^
<<blend_dir>>/blender/source/blender/makesdna/DNA_lightprobe_types.h:147:1: note: previous definition is here
BLI_STATIC_ASSERT_ALIGN(LightProbeCache, 16)
^
<<blend_dir>>/blender/source/blender/blenlib/BLI_assert.h:110:3: note: expanded from macro 'BLI_STATIC_ASSERT_ALIGN'
BLI_STATIC_ASSERT((sizeof(st) % (align) == 0), "Structure must be strictly aligned")
^
<<blend_dir>>/blender/source/blender/blenlib/BLI_assert.h:106:12: note: expanded from macro 'BLI_STATIC_ASSERT'
enum { _BLI_ASSERT_CONCAT(assert_line_, __LINE__) = 1 / (int)(!!(a)) };
^
<<blend_dir>>/blender/source/blender/blenlib/BLI_assert.h:99:36: note: expanded from macro '_BLI_ASSERT_CONCAT'
# define _BLI_ASSERT_CONCAT(a, b) _BLI_ASSERT_CONCAT_(a, b)
^
<<blend_dir>>/blender/source/blender/blenlib/BLI_assert.h:98:37: note: expanded from macro '_BLI_ASSERT_CONCAT_'
# define _BLI_ASSERT_CONCAT_(a, b) a##b
^
<scratch space>:17:1: note: expanded from here
assert_line_147
^