FTBFS: undefined reference to `round'
dos@yoga:~/git/purism/kgx/build$ ninja
[17/26] Linking target src/libkgx.so.
FAILED: src/libkgx.so
ccache cc -o src/libkgx.so 'src/25a6634@@kgx@sha/meson-generated_.._kgx-resources.c.o' 'src/25a6634@@kgx@sha/meson-generated_.._kgx-enums.c.o' 'src/25a6634@@kgx@sha/kgx-application.c.o' 'src/25a6634@@kgx@sha/fp-vte-util.c.o' 'src/25a6634@@kgx@sha/kgx-terminal.c.o' 'src/25a6634@@kgx@sha/kgx-search-box.c.o' 'src/25a6634@@kgx@sha/kgx-window.c.o' 'src/25a6634@@kgx@sha/kgx-process.c.o' -Wl,--no-undefined -Wl,--as-needed -shared -fPIC -Wl,--start-group -Wl,-soname,libkgx.so /usr/lib/libgio-2.0.so /usr/lib/libgobject-2.0.so /usr/lib/libglib-2.0.so /usr/lib/libgtk-3.so /usr/lib/libgdk-3.so /usr/lib/libz.so /usr/lib/libpangocairo-1.0.so /usr/lib/libpango-1.0.so /usr/lib/libharfbuzz.so /usr/lib/libatk-1.0.so /usr/lib/libcairo-gobject.so /usr/lib/libcairo.so /usr/lib/libgdk_pixbuf-2.0.so /usr/lib/libvte-2.91.so /usr/lib/libgtop-2.0.so -Wl,--end-group
/usr/bin/ld: src/25a6634@@kgx@sha/kgx-window.c.o: in function `font_scaled':
/home/dos/git/purism/kgx/build/../src/kgx-window.c:424: undefined reference to `round'
collect2: error: ld returned 1 exit status
[22/26] Compiling C object 'src/25a6634@@kgx@exe/kgx-search-box.c.o'.
ninja: build stopped: subcommand failed.