Symbolextractor fails when run on non utf8 locale

This happens with meson/ninja, but not with configure/make

[526/882] /usr/local/bin/python3.6 /tmp/tcloop/meson/usr/local/bin/meson --internal symbolextractor glib/libglib-2.0.so.0.5400.3 'glib/glib-2.0@sha/glib/libglib-2.0.so.0.5400.3.symbols' Warning: You are using 'ANSI_X3.4-1968' which is not a Unicode-compatible locale. You might see errors if you use UTF-8 strings as filenames, as strings, or as file contents. Please switch to a UTF-8 locale for your platform. ninja: build stopped: subcommand failed.