在 18.10 版本中，我发现某些应用程序（例如 Telegram）加载速度太慢。我发现原因有些fontconfig问题。
QEventLoop: Cannot be used without QApplication
Fontconfig warning: "/etc/fonts/conf.d/10-hinting-slight.conf", line 2: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/30-metric-aliases.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/30-metric-aliases.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/30-metric-aliases.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/30-metric-aliases.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/30-metric-aliases.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/30-metric-aliases.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/30-metric-aliases.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/40-nonlatin.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/40-nonlatin.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/40-nonlatin.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/40-nonlatin.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/40-nonlatin.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/40-nonlatin.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/40-nonlatin.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/45-generic.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/45-generic.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/45-generic.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/45-generic.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/45-generic.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/45-generic.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/45-generic.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/45-latin.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/45-latin.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/45-latin.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/45-latin.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/45-latin.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/45-latin.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/45-latin.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/49-sansserif.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/49-sansserif.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/49-sansserif.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/49-sansserif.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/49-sansserif.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/49-sansserif.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/49-sansserif.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/50-user.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/50-user.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/50-user.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/50-user.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/50-user.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/50-user.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/50-user.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/51-local.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/51-local.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/51-local.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/51-local.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/51-local.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/51-local.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/51-local.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/60-generic.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/60-generic.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/60-generic.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/60-generic.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/60-generic.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/60-generic.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/60-generic.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/60-latin.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/60-latin.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/60-latin.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/60-latin.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/60-latin.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/60-latin.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/60-latin.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/65-fonts-persian.conf", line 34: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/65-fonts-persian.conf", line 35: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/65-fonts-persian.conf", line 35: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/65-fonts-persian.conf", line 35: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/65-fonts-persian.conf", line 36: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/65-fonts-persian.conf", line 36: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/65-nonlatin.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/65-nonlatin.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/65-nonlatin.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/65-nonlatin.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/65-nonlatin.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/65-nonlatin.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/65-nonlatin.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/69-unifont.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/69-unifont.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/69-unifont.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/69-unifont.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/69-unifont.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/69-unifont.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/70-no-bitmaps.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/70-no-bitmaps.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/70-no-bitmaps.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/70-no-bitmaps.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/70-no-bitmaps.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/70-no-bitmaps.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/70-no-bitmaps.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/80-delicious.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/80-delicious.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/80-delicious.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/80-delicious.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/80-delicious.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/80-delicious.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/90-synthetic.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/90-synthetic.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/90-synthetic.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/90-synthetic.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/90-synthetic.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/90-synthetic.conf", line 6: invalid attribute 'version'
如何解决？