{
buildPackages,
writeText,
fontconfig,
lib,
runCommand,
stdenv,
}:
let
fontconfig' = fontconfig;
in
{
fontconfig ? fontconfig',
fontDirectories,
}:
let
fontDirsPath = writeText "font-dirs" ''
${lib.concatStringsSep "\n" (map (font: "
${font}") fontDirectories)}
'';
in
runCommand "fc-cache"
{
preferLocalBuild = true;
allowSubstitutes = false;
}
''
export FONTCONFIG_FILE=$(pwd)/fonts.conf
cat > fonts.conf << EOF
${fontconfig.out}/etc/fonts/fonts.conf$out
EOF
cat "${fontDirsPath}" >> fonts.conf
echo "" >> fonts.conf
# N.B.: fc-cache keys its cache entries by architecture.
# We must invoke the host `fc-cache` (not the build fontconfig) if we want
# the cache to be usable by the host.
mkdir -p $out
${stdenv.hostPlatform.emulator buildPackages} ${lib.getExe' fontconfig "fc-cache"} -sv
# This is not a cache dir in the normal sense -- it won't be automatically
# recreated.
rm -f "$out/CACHEDIR.TAG"
''