--- /dev/null
+https://bugs.gentoo.org/609366
+Backported from https://github.com/fmtlib/fmt.git:
+
+commit abbefd71666055daac9e14e78262620f9e845850
+Author: Victor Zverovich <victor.zverovich@gmail.com>
+Date: Wed Oct 19 06:52:55 2016 -0700
+
+ CHAR_WIDTH -> CHAR_SIZE to avoid collision with ISO/IEC TS 18661-1:2014 macro
+
+--- openMittsu-0.9.2_p78-orig/3rdparty/spdlog/include/spdlog/details/format.h
++++ openMittsu-0.9.2_p78/3rdparty/spdlog/include/spdlog/details/format.h
+@@ -2163,29 +2163,29 @@
+ typedef typename BasicWriter<Char>::CharPtr CharPtr;\r
+ Char fill = internal::CharTraits<Char>::cast(spec_.fill());\r
+ CharPtr out = CharPtr();\r
+- const unsigned CHAR_WIDTH = 1;\r
+- if (spec_.width_ > CHAR_WIDTH)\r
++ const unsigned CHAR_SIZE = 1;\r
++ if (spec_.width_ > CHAR_SIZE)\r
+ {\r
+ out = writer_.grow_buffer(spec_.width_);\r
+ if (spec_.align_ == ALIGN_RIGHT)\r
+ {\r
+- std::uninitialized_fill_n(out, spec_.width_ - CHAR_WIDTH, fill);\r
+- out += spec_.width_ - CHAR_WIDTH;\r
++ std::uninitialized_fill_n(out, spec_.width_ - CHAR_SIZE, fill);\r
++ out += spec_.width_ - CHAR_SIZE;\r
+ }\r
+ else if (spec_.align_ == ALIGN_CENTER)\r
+ {\r
+ out = writer_.fill_padding(out, spec_.width_,\r
+- internal::check(CHAR_WIDTH), fill);\r
++ internal::check(CHAR_SIZE), fill);\r
+ }\r
+ else\r
+ {\r
+- std::uninitialized_fill_n(out + CHAR_WIDTH,\r
+- spec_.width_ - CHAR_WIDTH, fill);\r
++ std::uninitialized_fill_n(out + CHAR_SIZE,\r
++ spec_.width_ - CHAR_SIZE, fill);\r
+ }\r
+ }\r
+ else\r
+ {\r
+- out = writer_.grow_buffer(CHAR_WIDTH);\r
++ out = writer_.grow_buffer(CHAR_SIZE);\r
+ }\r
+ *out = internal::CharTraits<Char>::cast(value);\r
+ }\r