Index: meson-0.50.0/data/macros.meson
===================================================================
--- meson-0.50.0.orig/data/macros.meson
+++ meson-0.50.0/data/macros.meson
@@ -1,9 +1,15 @@
 %__meson %{_bindir}/meson
 %__meson_wrap_mode nodownload
 %__meson_auto_features enabled
+%_vpath_srcdir .
+%_vpath_builddir build
 
 %meson \
-    %set_build_flags \
+    export LANG=C.UTF-8                      \
+    export CFLAGS="${CFLAGS:-%optflags}"     \
+    export CXXFLAGS="${CXXFLAGS:-%optflags}" \
+    export FFLAGS="${FFLAGS:-%optflags}"     \
+    export FCFLAGS="${FCFLAGS:-%optflags}"   \
     %{shrink:%{__meson} \
         --buildtype=plain \
         --prefix=%{_prefix} \
@@ -25,10 +31,13 @@
 	%{nil}}
 
 %meson_build \
+    export LANG=C.UTF-8                      \
     %ninja_build -C %{_vpath_builddir}
 
 %meson_install \
+    export LANG=C.UTF-8                      \
     %ninja_install -C %{_vpath_builddir}
 
 %meson_test \
+    export LANG=C.UTF-8                      \
     %ninja_test -C %{_vpath_builddir}