fontcache issue with rpm-ostree layered google-chrome and toolbox dnf-installed vscode - affects rendering of cjk-fonts & emoji glyphs

[christiansam]

International fonts (e.g. cjk fonts, but also emoji glyphs) stop working/being displayed in google-chrome (rpm-ostree layered) when vscode (toolbox dnf-installed) was running before.

• Firefox (rpm-ostree stock provided) is not affected by that issue and flawlessly displays international fonts at any time without of sideeffects .
• To get international fonts working again in google-chrome i have to delete ~/.cache/fontconfig/

For testing cjk-fonts: https://www.mingpao.com/
For testing emoji glyphs: https://unicode.org/emoji/charts/emoji-counts.html

rpm-ostree / google-chrome:

christian@host:~/.cache$ rpm-ostree status
State: idle
Deployments:
● fedora:fedora/39/x86_64/silverblue
                  Version: 39.20240309.0 (2024-03-09T00:38:54Z)
               BaseCommit: ee8d8c93e05e235db954d09708be8dd8ddaad223f3ee0596f1b67ae7500c81d9
             GPGSignature: Valid signature by E8F23996F23218640CB44CBE75CF5AC418B8E74C
          LayeredPackages: gnome-tweaks google-chrome-stable langpacks-de samba vim

christian@host:~/.cache$ rpm -qa google-chrome-stable
google-chrome-stable-122.0.6261.111-1.x86_64

christian@host:~/.cache$ rpm -qa |grep -i fontconfig
fontconfig-2.14.2-6.fc39.x86_64

christian@host:~/.cache$ fc-list |grep -i cjk|wc -l
100
christian@host:~/.cache$ fc-list |grep -i google |wc -l
397
christian@host:~/.cache$ fc-list |wc -l
562

toolbox / vscode:

CONTAINER ID  CONTAINER NAME     CREATED      STATUS   IMAGE NAME
0fa892f49d58  fedora-toolbox-39  5 weeks ago  running  registry.fedoraproject.org/fedora-toolbox:39

⬢[christian@toolbox .cache]$ rpm -q code
code-1.87.1-1709685844.el8.x86_64

⬢[christian@toolbox .cache]$ rpm -qa |grep font
fonts-filesystem-2.0.5-12.fc39.noarch
liberation-fonts-common-2.1.5-7.fc39.noarch
liberation-mono-fonts-2.1.5-7.fc39.noarch
liberation-sans-fonts-2.1.5-7.fc39.noarch
liberation-serif-fonts-2.1.5-7.fc39.noarch
abattis-cantarell-vf-fonts-0.301-10.fc39.noarch
default-fonts-core-sans-4.0-9.fc39.noarch
sil-mingzat-fonts-1.100-4.fc39.noarch
langpacks-fonts-en-4.0-9.fc39.noarch
adobe-source-code-pro-fonts-2.042.1.062.1.026-2.fc39.noarch
google-noto-fonts-common-20240101-1.fc39.noarch
google-noto-sans-vf-fonts-20240101-1.fc39.noarch

fontconfig-2.14.2-6.fc39.x86_64

google-noto-sans-mono-vf-fonts-20240101-1.fc39.noarch
google-noto-serif-vf-fonts-20240101-1.fc39.noarch


⬢[christian@toolbox .cache]$ fc-list |grep -i cjk|wc -l
0
⬢[christian@toolbox .cache]$ fc-list |grep -i google |wc -l
25
⬢[christian@toolbox .cache]$ fc-list |wc -l
58

State of a fresh purged fontconfig directory after vscode (toolbox/dnf) has been started:

christian@host:~/.cache$ ll fontconfig
insgesamt 124
-rw-r--r--. 1 christian christian  2304  9. Mär 21:42 0122acdcf386a94f53a6370d356e58f1-le64.cache-9
-rw-r--r--. 1 christian christian 10016  9. Mär 21:42 18f520a508f13854f77176faf7889ae9-le64.cache-9
-rw-r--r--. 1 christian christian   448  9. Mär 21:42 3830d5c3ddfd5cd38a049b759396e72e-le64.cache-9
-rw-r--r--. 1 christian christian  8280  9. Mär 21:42 3e9ca894d7ccd8b9fedb236c4f3f7c4e-le64.cache-9
-rw-r--r--. 1 christian christian  7632  9. Mär 21:42 5535e07303e0edee0923e77e4e59b69c-le64.cache-9
-rw-r--r--. 1 christian christian   200  9. Mär 21:42 CACHEDIR.TAG
-rw-r--r--. 1 christian christian  7808  9. Mär 21:42 cf759820c416606818fc74e5e9991313-le64.cache-9
-rw-r--r--. 1 christian christian 26664  9. Mär 21:42 d4fe5728f86380c2e3b1e4e9a34fabd8-le64.cache-9
-rw-r--r--. 1 christian christian 41280  9. Mär 21:42 d63f98f14a274bd69a5425fc33aaac6b-le64.cache-9

State of a fresh purged fontconfig directory after google-chrome (rpm-ostree) has been started:
note: there are several identical named entries

christian@host:~/.cache$ ll fontconfig
insgesamt 1056
-rw-r--r--. 1 christian christian   7216  9. Mär 21:43 01d40cee498be4726842ba21cbce24ab-le64.cache-9
-rw-r--r--. 1 christian christian   3920  9. Mär 21:43 0f80fa86029ae75a63f21d682b864529-le64.cache-9
-rw-r--r--. 1 christian christian 111424  9. Mär 21:43 123d59b33ddb0e7c76bb24004bd5cfac-le64.cache-9
-rw-r--r--. 1 christian christian  17712  9. Mär 21:43 131ab5cc1583381c4f7ce0194912c56d-le64.cache-9
-rw-r--r--. 1 christian christian  10016  9. Mär 21:43 18f520a508f13854f77176faf7889ae9-le64.cache-9
-rw-r--r--. 1 christian christian   2384  9. Mär 21:43 226d8b81908fffe4270cbbf5698029d4-le64.cache-9
-rw-r--r--. 1 christian christian   3480  9. Mär 21:43 22f06f3be2d16d058da85b73ae1dc5b1-le64.cache-9
-rw-r--r--. 1 christian christian  17480  9. Mär 21:43 29c8f5b6bf15d25ebb2e963855ab41be-le64.cache-9
-rw-r--r--. 1 christian christian  32296  9. Mär 21:43 2a3658b432e68423dcec456e1667e977-le64.cache-9
-rw-r--r--. 1 christian christian   1896  9. Mär 21:43 2a90ec7ec7fc01d3a9f58fddf8db0237-le64.cache-9
-rw-r--r--. 1 christian christian   9224  9. Mär 21:43 3196f05a030874ca00722cbf1e991434-le64.cache-9
-rw-r--r--. 1 christian christian   1392  9. Mär 21:43 3830d5c3ddfd5cd38a049b759396e72e-le64.cache-9
-rw-r--r--. 1 christian christian   2160  9. Mär 21:43 39377a11d38956c26ecfe23db50b3cd3-le64.cache-9
-rw-r--r--. 1 christian christian   8280  9. Mär 21:43 3e9ca894d7ccd8b9fedb236c4f3f7c4e-le64.cache-9
-rw-r--r--. 1 christian christian  77744  9. Mär 21:43 42536ef14367b24656ac994a93d66238-le64.cache-9
-rw-r--r--. 1 christian christian   7632  9. Mär 21:43 5535e07303e0edee0923e77e4e59b69c-le64.cache-9
-rw-r--r--. 1 christian christian  33000  9. Mär 21:43 6ee3103884cce7b2fe6f32eba9089175-le64.cache-9
-rw-r--r--. 1 christian christian   5552  9. Mär 21:43 7ee6df7a8311986241317a58487e0145-le64.cache-9
-rw-r--r--. 1 christian christian   2208  9. Mär 21:43 9d9e7a658cb1f50f02561d1ed3ca8bca-le64.cache-9
-rw-r--r--. 1 christian christian   2936  9. Mär 21:43 aa02322cc1375fea2382deabf4339973-le64.cache-9
-rw-r--r--. 1 christian christian   3656  9. Mär 21:43 b2307de753f1224d9542f27e8b3975ae-le64.cache-9
-rw-r--r--. 1 christian christian  77704  9. Mär 21:43 c4be257954870c0bf6972134c1de66d5-le64.cache-9
-rw-r--r--. 1 christian christian    200  9. Mär 21:43 CACHEDIR.TAG
-rw-r--r--. 1 christian christian  16672  9. Mär 21:43 cc8b894d3abbdf0310c48629c0737d80-le64.cache-9
-rw-r--r--. 1 christian christian   7808  9. Mär 21:43 cf759820c416606818fc74e5e9991313-le64.cache-9
-rw-r--r--. 1 christian christian  26664  9. Mär 21:43 d4fe5728f86380c2e3b1e4e9a34fabd8-le64.cache-9
-rw-r--r--. 1 christian christian 493608  9. Mär 21:43 d63f98f14a274bd69a5425fc33aaac6b-le64.cache-9
-rw-r--r--. 1 christian christian  44112  9. Mär 21:43 efcfae1a52990961975415036867654f-le64.cache-9

State of the fontconfig directory when google-chrome (rpm-ostree) started first, and afterwards toolbox run vscode (toolbox/dnf) was started.

• As long as google-chrome is still running cjk fonts or emoji glyphs get displayed
• When google-chrome is closed and started again cjk fonts or emoji glyphs won't get displayed

christian@host:~/.cache/fontconfig$ ls -ltrZ
insgesamt 620
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0    200  9. Mär 23:12 CACHEDIR.TAG
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   9224  9. Mär 23:12 3196f05a030874ca00722cbf1e991434-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   3920  9. Mär 23:12 0f80fa86029ae75a63f21d682b864529-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  33000  9. Mär 23:12 6ee3103884cce7b2fe6f32eba9089175-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   5552  9. Mär 23:12 7ee6df7a8311986241317a58487e0145-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   2936  9. Mär 23:12 aa02322cc1375fea2382deabf4339973-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  77704  9. Mär 23:12 c4be257954870c0bf6972134c1de66d5-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  44112  9. Mär 23:12 efcfae1a52990961975415036867654f-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  77744  9. Mär 23:12 42536ef14367b24656ac994a93d66238-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   3480  9. Mär 23:12 22f06f3be2d16d058da85b73ae1dc5b1-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  32296  9. Mär 23:12 2a3658b432e68423dcec456e1667e977-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   1896  9. Mär 23:12 2a90ec7ec7fc01d3a9f58fddf8db0237-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  17480  9. Mär 23:12 29c8f5b6bf15d25ebb2e963855ab41be-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   2208  9. Mär 23:12 9d9e7a658cb1f50f02561d1ed3ca8bca-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   2160  9. Mär 23:12 39377a11d38956c26ecfe23db50b3cd3-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   7216  9. Mär 23:12 01d40cee498be4726842ba21cbce24ab-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   2384  9. Mär 23:12 226d8b81908fffe4270cbbf5698029d4-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   3656  9. Mär 23:12 b2307de753f1224d9542f27e8b3975ae-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  17712  9. Mär 23:12 131ab5cc1583381c4f7ce0194912c56d-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0 111424  9. Mär 23:12 123d59b33ddb0e7c76bb24004bd5cfac-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  16672  9. Mär 23:12 cc8b894d3abbdf0310c48629c0737d80-le64.cache-9

-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0    448 10. Mär 10:12 3830d5c3ddfd5cd38a049b759396e72e-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  10016 10. Mär 10:12 18f520a508f13854f77176faf7889ae9-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  26664 10. Mär 10:12 d4fe5728f86380c2e3b1e4e9a34fabd8-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0  41280 10. Mär 10:12 d63f98f14a274bd69a5425fc33aaac6b-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   7808 10. Mär 10:12 cf759820c416606818fc74e5e9991313-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   7632 10. Mär 10:12 5535e07303e0edee0923e77e4e59b69c-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   8280 10. Mär 10:12 3e9ca894d7ccd8b9fedb236c4f3f7c4e-le64.cache-9
-rw-r--r--. 1 christian christian unconfined_u:object_r:user_fonts_cache_t:s0   2304 10. Mär 10:12 0122acdcf386a94f53a6370d356e58f1-le64.cache-9

[christiansam]

idk if this is relevant, but upon further inspection for other - systemwide - fontcache locations i stumbled upon the following (r/o, inmutable) path /usr/lib/fontconfig/cache.

• from what i've read about fontconfig the 1970-01-01 date seem to be a workaround/hack
• regarding the -8 suffix i don't have a clue if this is some sort of convention (fontconfig version-related?) or another workaround/hack?

root@host:/usr/lib/fontconfig# ll
drwxr-xr-x. 1 root root 2454  1. Jän 1970  cache

root@host:/usr/lib/fontconfig# ll cache/
insgesamt 1024
-rw-r--r--. 5 root root   7024  1. Jän 1970  01d40cee498be4726842ba21cbce24ab-le64.cache-8
-rw-r--r--. 5 root root   3872  1. Jän 1970  0f80fa86029ae75a63f21d682b864529-le64.cache-8
-rw-r--r--. 3 root root 108112  1. Jän 1970  123d59b33ddb0e7c76bb24004bd5cfac-le64.cache-8
-rw-r--r--. 5 root root  17280  1. Jän 1970  131ab5cc1583381c4f7ce0194912c56d-le64.cache-8
-rw-r--r--. 5 root root   9728  1. Jän 1970  18f520a508f13854f77176faf7889ae9-le64.cache-8
-rw-r--r--. 5 root root   2336  1. Jän 1970  226d8b81908fffe4270cbbf5698029d4-le64.cache-8
-rw-r--r--. 5 root root   3432  1. Jän 1970  22f06f3be2d16d058da85b73ae1dc5b1-le64.cache-8
-rw-r--r--. 5 root root  17000  1. Jän 1970  29c8f5b6bf15d25ebb2e963855ab41be-le64.cache-8
-rw-r--r--. 5 root root  31432  1. Jän 1970  2a3658b432e68423dcec456e1667e977-le64.cache-8
-rw-r--r--. 5 root root   1848  1. Jän 1970  2a90ec7ec7fc01d3a9f58fddf8db0237-le64.cache-8
-rw-r--r--. 5 root root   8984  1. Jän 1970  3196f05a030874ca00722cbf1e991434-le64.cache-8
-rw-r--r--. 2 root root   1392  1. Jän 1970  3830d5c3ddfd5cd38a049b759396e72e-le64.cache-8
-rw-r--r--. 5 root root   2112  1. Jän 1970  39377a11d38956c26ecfe23db50b3cd3-le64.cache-8
-rw-r--r--. 4 root root   8088  1. Jän 1970  3e9ca894d7ccd8b9fedb236c4f3f7c4e-le64.cache-8
-rw-r--r--. 5 root root  75824  1. Jän 1970  42536ef14367b24656ac994a93d66238-le64.cache-8
-rw-r--r--. 4 root root   7440  1. Jän 1970  5535e07303e0edee0923e77e4e59b69c-le64.cache-8
-rw-r--r--. 5 root root  32232  1. Jän 1970  6ee3103884cce7b2fe6f32eba9089175-le64.cache-8
-rw-r--r--. 3 root root   5456  1. Jän 1970  7ee6df7a8311986241317a58487e0145-le64.cache-8
-rw-r--r--. 5 root root   2160  1. Jän 1970  9d9e7a658cb1f50f02561d1ed3ca8bca-le64.cache-8
-rw-r--r--. 5 root root   2888  1. Jän 1970  aa02322cc1375fea2382deabf4339973-le64.cache-8
-rw-r--r--. 5 root root   3560  1. Jän 1970  b2307de753f1224d9542f27e8b3975ae-le64.cache-8
-rw-r--r--. 5 root root  75784  1. Jän 1970  c4be257954870c0bf6972134c1de66d5-le64.cache-8
-rw-r--r--. 5 root root    200  1. Jän 1970  CACHEDIR.TAG
-rw-r--r--. 5 root root  16192  1. Jän 1970  cc8b894d3abbdf0310c48629c0737d80-le64.cache-8
-rw-r--r--. 5 root root   7616  1. Jän 1970  cf759820c416606818fc74e5e9991313-le64.cache-8
-rw-r--r--. 5 root root  25992  1. Jän 1970  d4fe5728f86380c2e3b1e4e9a34fabd8-le64.cache-8
-rw-r--r--. 3 root root 478872  1. Jän 1970  d63f98f14a274bd69a5425fc33aaac6b-le64.cache-8
-rw-r--r--. 5 root root  43152  1. Jän 1970  efcfae1a52990961975415036867654f-le64.cache-8

[christiansam]

fyi: i've created a fresh new toolbox from scratch from the stock baseimage registry.fedoraproject.org/fedora-toolbox:39 because i wanted to rule out side-effects of other installed packages like vim-X11, or several performed dnf upgrade in general.

so in the new created toolbox:

• i didn't run dnf upgrade to update the provided stock packages of the containerized fedora39
• the only thing i did was to install vscode - via dnf install code, of course this goes along with a bunch of installed dependencies like fontconfig, libXft, etc.

after i had started vscode in the new toolbox:

• the same state in ~/.cache/fontconfig was present as noted in the posts before
• after i restarted google-chrome cjk-fonts & emoji glyphs did not render properly

---

btw:

• i don't know anything how fonconfig is supposed to work, but just in case if fc-cache is run - either on the host (rpm-ostree install) or inside a toolbox (dnf install) - because in both ways this result in something written to ~/.cache/fontconfig.
• does fontconfig/fc-cache depend on, that in both cases/environments the same fonts are present?

because:

christian@host:~$ rpm -qa |grep -i font |grep noarch |wc -l
146

christian@host:~$ rpm -qa |grep -i font |grep cjk
google-noto-sans-mono-cjk-vf-fonts-2.004-5.fc39.noarch
google-noto-sans-cjk-vf-fonts-2.004-5.fc39.noarch
google-noto-serif-cjk-vf-fonts-2.002-2.fc39.noarch
default-fonts-cjk-serif-4.0-9.fc39.noarch
default-fonts-cjk-sans-4.0-9.fc39.noarch
default-fonts-cjk-mono-4.0-9.fc39.noarch

christian@host:~$ fc-list | wc -l
562

⬢[christian@toolbox ~]$ rpm -qa |grep -i font |grep noarch |wc -l
14

⬢[christian@toolbox ~]$ rpm -qa |grep -i font |grep cjk |wc -l
0

⬢[christian@toolbox ~]$ fc-list |wc -l
58

[christiansam]

here is a workaround for the issue:

• to my understanding /usr/share/ inside the toolbox container is an independent/seperate resource (container-volume) and not a host's bind-mount like e.g. the home directories (~)
• so, copy (maybe symlinks would work too?) the fontconfig/ and fonts/ from the host's /usr/share to the respective path in the toolbox container

⬢[christian@toolbox ~]$ sudo -i

⬢[root@toolbox ~]#
cd /usr/share/

mv fontconfig fontconfig_bkp
mv fonts fonts_bkp

cp -r /run/host/usr/share/fontconfig/ .
cp -r /run/host/usr/share/fonts/ .

exit

⬢[christian@toolbox share]$ fc-list|grep -i cjk
/usr/share/fonts/google-noto-sans-mono-cjk-vf-fonts/NotoSansMonoCJK-VF.ttc: Noto Sans Mono CJK SC:style=Medium
/usr/share/fonts/google-noto-sans-mono-cjk-vf-fonts/NotoSansMonoCJK-VF.ttc: Noto Sans Mono CJK TC:style=Medium
/usr/share/fonts/google-noto-sans-mono-cjk-vf-fonts/NotoSansMonoCJK-VF.ttc: Noto Sans Mono CJK JP:style=Medium
/usr/share/fonts/google-noto-sans-mono-cjk-vf-fonts/NotoSansMonoCJK-VF.ttc: Noto Sans Mono CJK HK:style=Medium
/usr/share/fonts/google-noto-sans-mono-cjk-vf-fonts/NotoSansMonoCJK-VF.ttc: Noto Sans Mono CJK KR:style=Medium
/usr/share/fonts/google-noto-sans-cjk-vf-fonts/NotoSansCJK-VF.ttc: Noto Sans CJK TC:style=Bold
...

[travier]

This looks a lot like #534. Can you check if this is a duplicate?

[christiansam]

In terms of the described fontconfig cache issue:

To my knowledge flatpak is able to serve applications the means of individual locations to provide app.-specific font collections along seperated locations to store the fontconfig caches. All locations are isolated per application and are also distinct from respective locations of the host environment

• /var/home/christian/.var/app/io.podman_desktop.PodmanDesktop/cache/fontconfig/03a3974e20a7d4a4c13001180806a005-le64.cache-9
• /var/lib/flatpak/runtime/org.gnome.Platform/x86_64/45/a7e98d7b10776989dc22e866ce672c14d3db0a20c509fbbc6c960e3ed26d28e6/files/cache/fontconfig/03a3974e20a7d4a4c13001180806a005-le64.cache-9

While fonts in a toolbox environment, along fonts of the host environment, reside in seperated locations too and will likely represent different font collections, the fontconfig cache directory - located at ~/.cache/fontconfig - is reduced to a single location and so prone to name collisions.

i assume edge-cases like this are unwanted sideeffects of a toolbox's "shared" or bind-mounted home-directory

So regarding your question: "do you consider this a duplicate?"

• While at first glance the effect of mis-rendered font-characters in flatpak and non-flatpak-based applications might feel simliar
• I'm pretty sure that a solution for the desribed fontconfig (cache) issue has to pay attribute for the different concepts of isolation-behavior in toolbox and flatpak environments and also in respect to the host environment

[tenturestept]

I'm also having this issue and it does seem quite silly that toolbx defaults to sharing ~/.cache across containers.

@christiansam when you go to chrome://settings/fonts, which fonts are listed in the dropdown menus?

[christiansam]

• Standardschrift: Benutzerdefiniert (guess this means "custom" in english)

id="standardFontPreview" style="font-size: 16px; font-family: "Times New Roman";">

• Schriftart Serif: Benutzerdefiniert

id="serifFontPreview" style="font-size: 16px; font-family: "Times New Roman";">

• Schriftart Sans-Serif: Benutzerdefiniert

id="sansSerifFontPreview" style="font-size: 16px; font-family: Arial;">

• Schriftart mit fester Breite: Monospace

id="fixedFontPreview" style="font-size: 13px; font-family: Monospace;">

• Mathematische Schriftart: Benutzerdefiniert

id="mathFontPreview" style="font-size: 16px; font-family: "Latin Modern Math";">

[francoism90]

I had the same issue, to solve it:

# fc-cache -v
$ fc-cache -v

I don' t know if root and user are needed, but it work.

[christiansam]

I'm quite sure that regenerating the fonts cache would only work if you have the same fonts available/installed in your host and toolbox environment. (see my first post: #540 (comment))

Host:

christian@host:~/.cache$ fc-list |wc -l
562

Toolbox:

⬢[christian@toolbox .cache]$ fc-list |wc -l
58