Linux Mint 21 にアップグレードしてから Firefox とかのフォントがちょっとギザギザしている感じがしていました。ワタシの視力が良くなり？前は気にならなかったものが気になるようになったのではと思ったりもしました。
結論から言うと、fc-cache コマンドでフォントキャッシュを更新するとアップグレード前と同じようなキレイなフォントが復活しました。
以前は Noto Sans CJK が好きだったのですが、最近は IBM Plex Sans JP がお気に入りです。fc-list コマンドにフォント名を指定するとインストール先のディレクトリ名がわかります。自分であとから追加インストールしたフォントは /home/ユーザー名/.local/ 配下にインストールされているようです。
$ fc-list "IBM Plex Sans JP" /home/xxxxxxxx/.local/share/fonts/IBMPlexSansJP-Text.otf: IBM Plex Sans JP,IBM Plex Sans JP Text:style=Text,Regular /home/xxxxxxxx/.local/share/fonts/IBMPlexSansJP-Regular.otf: IBM Plex Sans JP:style=Regular /home/xxxxxxxx/.local/share/fonts/IBMPlexSansJP-ExtraLight.otf: IBM Plex Sans JP,IBM Plex Sans JP ExtLt:style=ExtraLight,Regular /home/xxxxxxxx/.local/share/fonts/IBMPlexSansJP-Thin.otf: IBM Plex Sans JP,IBM Plex Sans JP Thin:style=Thin,Regular /home/xxxxxxxx/.local/share/fonts/IBMPlexSansJP-Medium.otf: IBM Plex Sans JP,IBM Plex Sans JP Medm:style=Medium,Regular /home/xxxxxxxx/.local/share/fonts/IBMPlexSansJP-Bold.otf: IBM Plex Sans JP:style=Bold /home/xxxxxxxx/.local/share/fonts/IBMPlexSansJP-Light.otf: IBM Plex Sans JP,IBM Plex Sans JP Light:style=Light,Regular /home/xxxxxxxx/.local/share/fonts/IBMPlexSansJP-SemiBold.otf: IBM Plex Sans JP,IBM Plex Sans JP SmBld:style=SemiBold,Regular
IBM Plex Sans JP の Github には 6.0.2 というバージョンがリリースされていましたが、ワタシがインストールしていたのは 6.0.0 かもしれません。
試しに再度フォントをインストールし直そうということで、.local/ からフォントファイルを削除し、再度インストール後に反映のために fc-cache -fv コマンドを投入したというわけです。
fc-cache コマンドの結果はこちら。
$ fc-cache -fv /usr/share/fonts: caching, new cache contents: 0 fonts, 6 dirs /usr/share/fonts/X11: caching, new cache contents: 0 fonts, 4 dirs /usr/share/fonts/X11/Type1: caching, new cache contents: 8 fonts, 0 dirs /usr/share/fonts/X11/encodings: caching, new cache contents: 0 fonts, 1 dirs /usr/share/fonts/X11/encodings/large: caching, new cache contents: 0 fonts, 0 dirs /usr/share/fonts/X11/misc: caching, new cache contents: 89 fonts, 0 dirs /usr/share/fonts/X11/util: caching, new cache contents: 0 fonts, 0 dirs /usr/share/fonts/cMap: caching, new cache contents: 0 fonts, 0 dirs /usr/share/fonts/cmap: caching, new cache contents: 0 fonts, 5 dirs /usr/share/fonts/cmap/adobe-cns1: caching, new cache contents: 0 fonts, 0 dirs /usr/share/fonts/cmap/adobe-gb1: caching, new cache contents: 0 fonts, 0 dirs /usr/share/fonts/cmap/adobe-japan1: caching, new cache contents: 0 fonts, 0 dirs /usr/share/fonts/cmap/adobe-japan2: caching, new cache contents: 0 fonts, 0 dirs /usr/share/fonts/cmap/adobe-korea1: caching, new cache contents: 0 fonts, 0 dirs /usr/share/fonts/opentype: caching, new cache contents: 0 fonts, 6 dirs /usr/share/fonts/opentype/ipafont-mincho: caching, new cache contents: 2 fonts, 0 dirs /usr/share/fonts/opentype/linux-libertine: caching, new cache contents: 13 fonts, 0 dirs /usr/share/fonts/opentype/malayalam: caching, new cache contents: 7 fonts, 0 dirs /usr/share/fonts/opentype/mathjax: caching, new cache contents: 24 fonts, 0 dirs /usr/share/fonts/opentype/noto: caching, new cache contents: 80 fonts, 0 dirs /usr/share/fonts/opentype/urw-base35: caching, new cache contents: 35 fonts, 0 dirs /usr/share/fonts/truetype: caching, new cache contents: 2 fonts, 52 dirs /usr/share/fonts/truetype/Gargi: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/Gubbi: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/Nakula: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/Navilu: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/Sahadeva: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/Sarai: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/abyssinica: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/crosextra: caching, new cache contents: 8 fonts, 0 dirs /usr/share/fonts/truetype/dejavu: caching, new cache contents: 22 fonts, 0 dirs /usr/share/fonts/truetype/droid: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/fonts-beng-extra: caching, new cache contents: 6 fonts, 0 dirs /usr/share/fonts/truetype/fonts-deva-extra: caching, new cache contents: 3 fonts, 0 dirs /usr/share/fonts/truetype/fonts-gujr-extra: caching, new cache contents: 5 fonts, 0 dirs /usr/share/fonts/truetype/fonts-guru-extra: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/fonts-kalapi: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/fonts-orya-extra: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/fonts-telu-extra: caching, new cache contents: 2 fonts, 0 dirs /usr/share/fonts/truetype/fonts-yrsa-rasa: caching, new cache contents: 15 fonts, 0 dirs /usr/share/fonts/truetype/freefont: caching, new cache contents: 12 fonts, 0 dirs /usr/share/fonts/truetype/gentium: caching, new cache contents: 4 fonts, 0 dirs /usr/share/fonts/truetype/gentium-basic: caching, new cache contents: 8 fonts, 0 dirs /usr/share/fonts/truetype/kacst: caching, new cache contents: 15 fonts, 0 dirs /usr/share/fonts/truetype/kacst-one: caching, new cache contents: 2 fonts, 0 dirs /usr/share/fonts/truetype/lao: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/liberation: caching, new cache contents: 16 fonts, 0 dirs /usr/share/fonts/truetype/liberation2: caching, new cache contents: 12 fonts, 0 dirs /usr/share/fonts/truetype/libreoffice: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-assamese: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-bengali: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-devanagari: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-gujarati: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-kannada: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-malayalam: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-oriya: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-punjabi: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-tamil: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-tamil-classical: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/lohit-telugu: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/malayalam: caching, new cache contents: 10 fonts, 0 dirs /usr/share/fonts/truetype/noto: caching, new cache contents: 1848 fonts, 0 dirs /usr/share/fonts/truetype/padauk: caching, new cache contents: 4 fonts, 0 dirs /usr/share/fonts/truetype/pagul: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/samyak: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/samyak-fonts: caching, new cache contents: 3 fonts, 0 dirs /usr/share/fonts/truetype/sinhala: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/takao-gothic: caching, new cache contents: 2 fonts, 0 dirs /usr/share/fonts/truetype/takao-mincho: caching, new cache contents: 2 fonts, 0 dirs /usr/share/fonts/truetype/teluguvijayam: caching, new cache contents: 20 fonts, 0 dirs /usr/share/fonts/truetype/tibetan-machine: caching, new cache contents: 1 fonts, 0 dirs /usr/share/fonts/truetype/tlwg: caching, new cache contents: 58 fonts, 0 dirs /usr/share/fonts/truetype/ttf-khmeros-core: caching, new cache contents: 2 fonts, 0 dirs /usr/share/fonts/truetype/ubuntu: caching, new cache contents: 14 fonts, 0 dirs /usr/share/fonts/type1: caching, new cache contents: 0 fonts, 2 dirs /usr/share/fonts/type1/gsfonts: caching, new cache contents: 35 fonts, 0 dirs /usr/share/fonts/type1/urw-base35: caching, new cache contents: 35 fonts, 0 dirs /usr/local/share/fonts: caching, new cache contents: 0 fonts, 0 dirs /home/xxxxxxxx/.local/share/fonts: caching, new cache contents: 9 fonts, 0 dirs /home/xxxxxxxx/.fonts: skipping, no such directory /usr/share/fonts/X11: skipping, looped directory detected /usr/share/fonts/cMap: skipping, looped directory detected /usr/share/fonts/cmap: skipping, looped directory detected /usr/share/fonts/opentype: skipping, looped directory detected /usr/share/fonts/truetype: skipping, looped directory detected /usr/share/fonts/type1: skipping, looped directory detected /usr/share/fonts/X11/Type1: skipping, looped directory detected /usr/share/fonts/X11/encodings: skipping, looped directory detected /usr/share/fonts/X11/misc: skipping, looped directory detected /usr/share/fonts/X11/util: skipping, looped directory detected /usr/share/fonts/cmap/adobe-cns1: skipping, looped directory detected /usr/share/fonts/cmap/adobe-gb1: skipping, looped directory detected /usr/share/fonts/cmap/adobe-japan1: skipping, looped directory detected /usr/share/fonts/cmap/adobe-japan2: skipping, looped directory detected /usr/share/fonts/cmap/adobe-korea1: skipping, looped directory detected /usr/share/fonts/opentype/ipafont-mincho: skipping, looped directory detected /usr/share/fonts/opentype/linux-libertine: skipping, looped directory detected /usr/share/fonts/opentype/malayalam: skipping, looped directory detected /usr/share/fonts/opentype/mathjax: skipping, looped directory detected /usr/share/fonts/opentype/noto: skipping, looped directory detected /usr/share/fonts/opentype/urw-base35: skipping, looped directory detected /usr/share/fonts/truetype/Gargi: skipping, looped directory detected /usr/share/fonts/truetype/Gubbi: skipping, looped directory detected /usr/share/fonts/truetype/Nakula: skipping, looped directory detected /usr/share/fonts/truetype/Navilu: skipping, looped directory detected /usr/share/fonts/truetype/Sahadeva: skipping, looped directory detected /usr/share/fonts/truetype/Sarai: skipping, looped directory detected /usr/share/fonts/truetype/abyssinica: skipping, looped directory detected /usr/share/fonts/truetype/crosextra: skipping, looped directory detected /usr/share/fonts/truetype/dejavu: skipping, looped directory detected /usr/share/fonts/truetype/droid: skipping, looped directory detected /usr/share/fonts/truetype/fonts-beng-extra: skipping, looped directory detected /usr/share/fonts/truetype/fonts-deva-extra: skipping, looped directory detected /usr/share/fonts/truetype/fonts-gujr-extra: skipping, looped directory detected /usr/share/fonts/truetype/fonts-guru-extra: skipping, looped directory detected /usr/share/fonts/truetype/fonts-kalapi: skipping, looped directory detected /usr/share/fonts/truetype/fonts-orya-extra: skipping, looped directory detected /usr/share/fonts/truetype/fonts-telu-extra: skipping, looped directory detected /usr/share/fonts/truetype/fonts-yrsa-rasa: skipping, looped directory detected /usr/share/fonts/truetype/freefont: skipping, looped directory detected /usr/share/fonts/truetype/gentium: skipping, looped directory detected /usr/share/fonts/truetype/gentium-basic: skipping, looped directory detected /usr/share/fonts/truetype/kacst: skipping, looped directory detected /usr/share/fonts/truetype/kacst-one: skipping, looped directory detected /usr/share/fonts/truetype/lao: skipping, looped directory detected /usr/share/fonts/truetype/liberation: skipping, looped directory detected /usr/share/fonts/truetype/liberation2: skipping, looped directory detected /usr/share/fonts/truetype/libreoffice: skipping, looped directory detected /usr/share/fonts/truetype/lohit-assamese: skipping, looped directory detected /usr/share/fonts/truetype/lohit-bengali: skipping, looped directory detected /usr/share/fonts/truetype/lohit-devanagari: skipping, looped directory detected /usr/share/fonts/truetype/lohit-gujarati: skipping, looped directory detected /usr/share/fonts/truetype/lohit-kannada: skipping, looped directory detected /usr/share/fonts/truetype/lohit-malayalam: skipping, looped directory detected /usr/share/fonts/truetype/lohit-oriya: skipping, looped directory detected /usr/share/fonts/truetype/lohit-punjabi: skipping, looped directory detected /usr/share/fonts/truetype/lohit-tamil: skipping, looped directory detected /usr/share/fonts/truetype/lohit-tamil-classical: skipping, looped directory detected /usr/share/fonts/truetype/lohit-telugu: skipping, looped directory detected /usr/share/fonts/truetype/malayalam: skipping, looped directory detected /usr/share/fonts/truetype/noto: skipping, looped directory detected /usr/share/fonts/truetype/padauk: skipping, looped directory detected /usr/share/fonts/truetype/pagul: skipping, looped directory detected /usr/share/fonts/truetype/samyak: skipping, looped directory detected /usr/share/fonts/truetype/samyak-fonts: skipping, looped directory detected /usr/share/fonts/truetype/sinhala: skipping, looped directory detected /usr/share/fonts/truetype/takao-gothic: skipping, looped directory detected /usr/share/fonts/truetype/takao-mincho: skipping, looped directory detected /usr/share/fonts/truetype/teluguvijayam: skipping, looped directory detected /usr/share/fonts/truetype/tibetan-machine: skipping, looped directory detected /usr/share/fonts/truetype/tlwg: skipping, looped directory detected /usr/share/fonts/truetype/ttf-khmeros-core: skipping, looped directory detected /usr/share/fonts/truetype/ubuntu: skipping, looped directory detected /usr/share/fonts/type1/gsfonts: skipping, looped directory detected /usr/share/fonts/type1/urw-base35: skipping, looped directory detected /usr/share/fonts/X11/encodings/large: skipping, looped directory detected /var/cache/fontconfig: not cleaning unwritable cache directory /home/xxxxxxxx/.cache/fontconfig: cleaning cache directory /home/xxxxxxxx/.cache/fontconfig: invalid cache file: d5178ab6d91b49bf20a416737dcea9e8-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: d3e5c4ee2ceb1fc347f91d4cefc53bc0-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 22368d551a680bfe5a62c02760edf4ea-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 56cf4f4769d0f4abc89a4895d7bd3ae1-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 49f0de54bdd920fe4f0dfd4cbac43e6b-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 674d1711f2d1d2a09646eb0bdcadee49-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 188ac73a183f12857f63bb60a4a6d603-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 57e423e26b20ab21d0f2f29c145174c3-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 707971e003b4ae6c8121c3a920e507f5-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 3f589640d34b7dc9042c8d453f7c8b9c-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: e49e89034d371f0f9de17aab02136486-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: f6e6e0a5c3d2f6ae0c0c2e0ecd42a997-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 3830d5c3ddfd5cd38a049b759396e72e-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 4b14b093aebc79c320de5e86ae1d3314-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 6c08beecf0dac481ec92e759e0c2e6d7-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: a48eab177a16e4f3713381162db2f3e9-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: a4e60e8d1e10d2fdff3fe3037a1845fb-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: b47c4e1ecd0709278f4910c18777a504-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: d82eb4fd963d448e2fcb7d7b793b5df3-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: e13b20fdb08344e0e664864cc2ede53d-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 4b2eda6bb976bda485cb2176619421d5-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 573ec803664ed168555e0e8b6d0f0c7f-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 6afa1bb216ce958c1589e297e8008489-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 3f7329c5293ffd510edef78f73874cfd-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 85e0a52ce643a7ba2ae53e5d6949cead-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 0bd3dc0958fa2205aaaa8ebb13e2872b-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 7ab2eb8330e5664a2b0e875ad8d37ad9-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: b872e6e592da6075ffa4ab0a1fcc0c75-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 3047814df9a2f067bd2d96a2b9c36e5a-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: fe547fea3a41b43a38975d292a2b19c7-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: f259c2cffa685e28062317905db73c4a-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 4794a0821666d79190d59a36cb4f44b5-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 2300eef321c393bfd76478a5c0e95b23-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: f1f2465696798768e9653f19e17ccdc8-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 4d9c95eba1cb85bbcf2878543262124a-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 53d14c92082a93e67d5078324eb314ca-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: d52a8644073d54c13679302ca1180695-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 6b2c5944714ca7831b25bed9e85cb5c8-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 6cc790b63b123a6a96ee260fcdad32a9-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 4c599c202bc5c08e2d34565a40eac3b2-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 246184dc75a16901ca37d96895904249-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: def309198bfa603429122923fa2bb2d4-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 370e5b74bf5dafc30834de68e24a87a4-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 04aabc0a78ac019cf9454389977116d2-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 1ac9eb803944fde146138c791f5cc56a-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 2171a34dccabdb6bcbbc728186263178-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 660208299946a285a940457d1287da33-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: e52a45a1c8c8fe895fc0fc8c4e6999b8-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: b9d506c9ac06c20b433354fa67a72993-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 6333f38776742d18e214673cd2c24e34-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: cabbd14511b9e8a55e92af97fb3a0461-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: c5c45a61289222e0d30b1a26ef4effbe-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 95530828ff6c81d309f8258d8d02a23e-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 945677eb7aeaf62f1d50efc3fb3ec7d8-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: f6d4eedfaab2589bde49f7a3ff831d22-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 9d2451b1fd30e5bffe8383fd27c35478-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 4f3e3037c9980c83b53a9351efadef62-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: aec30016f93e1b46d1a973dce0d74068-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: c855463f699352c367813e37f3f70ea7-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 16c2fda60d1b4b719f4b3d06fd951d25-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: d589a48862398ed80a3d6066f4f56f4c-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 14a5e22175779b556eaa434240950366-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 385c0604a188198f04d133e54aba7fe7-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 564b2e68ac9bc4e36a6f7f6d6125ec1c-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 550f3886151c940c12a5ed35f6a00586-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: dc05db6664285cc2f12bf69c139ae4c3-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: bab58bb527bb656aaa9f116d68a48d89-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 767a8244fc0220cfb567a839d0392e0b-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 0c9eb80ebd1c36541ebe2852d3bb0c49-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 0d8c3b2ac0904cb8a57a757ad11a4a08-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: eb48934c523a49add3824bfad8846c40-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: d0972c3d32f097851eb916381fc38920-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 589f83ef4c36d296ce6e1c846f468f08-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 551ecf3b0e8b0bca0f25c0944f561853-le64.cache-7 /home/xxxxxxxx/.cache/fontconfig: invalid cache file: 32b6488e5b8292a2e95c79d947e009e8-le64.cache-7 /home/xxxxxxxx/.fontconfig: not cleaning non-existent cache directory fc-cache: succeeded
あれ？いま見返すと /var/cache/fontconfig: not cleaning unwritable cache directory なんてメッセージも出力されていますね。これは sudo を付けてもう一度 fc-cache コマンドを投入しても良さそうです。
一度生成したフォントキャッシュは /home 配下のものを優先して使用しているのですかね。ワタシの環境では /home ディレクトリはシステムディレクトリとは別パーティションに配置しているので、OS のバージョンには引きづられず使い回すようになっています。定期的に fc-cache コマンドを投入してフォントキャッシュを更新した方が良さそうです。
ちなみに「フォントの選択」という設定画面の下段にアンチエイリアスなどの設定項目がありますが、「ヒンティング」は「微小」、「アンチエイリアス」は「RGBA」、「RGBAオーダー」は「RGB」で落ち着きました。
当初はここの設定を一生懸命に調整してみたり、もう時代は HiDPI なのかと思って 4K ディスプレイを物色したりと変な方向に走ってしまいましたが、フォントキャッシュの更新で解決したので良かったです。
でも、4K ディスプレイでも HiDPI も試してみたいですよね。GPU 負荷とかも上がっちゃうんでしょうねぇ。