Public bug reported: After upgrading to Ubuntu 26.04.1, multiple unrelated Flatpak applications crash with SIGSEGV/general protection fault inside libfontconfig.so.1.16.0.
Affected applications: - org.telegram.desktop, GNOME Platform 50 - com.rtosta.zapzap, KDE Platform 6.11 The crash is reproducible after a cold boot. The host resolves sans-serif correctly: /usr/share/fonts/truetype/noto/NotoSans-Regular.ttf family: Noto Sans style: Regular Inside both Flatpak sandboxes, fontconfig incorrectly resolved sans- serif to: /run/host/fonts/woff/ebgaramond/EBGaramond08-Italic.woff It also returned this WOFF font with a long incorrect family substitution list starting with DejaVu Sans and an empty style. The WOFF file belongs to the official Ubuntu package: fonts-ebgaramond-extra The file itself can be successfully parsed by fc-scan. Telegram consistently crashes at: /usr/lib/x86_64-linux-gnu/libfontconfig.so.1.16.0 + 0xc24c Workaround: 1. Move /usr/share/fonts/woff/ebgaramond outside the font search path. 2. Rebuild the system and user fontconfig caches. 3. After this, the Flatpak correctly selects DejaVuSans.ttf. 4. Telegram and ZapZap work, including after a complete poweroff and cold boot. This appears related to Flatpak upstream issue #6738: https://github.com/flatpak/flatpak/issues/6738 Expected: Flatpak applications should resolve sans-serif correctly and not crash when fonts-ebgaramond-extra is installed. Actual: The Flatpak font configuration selects an EB Garamond WOFF italic font as sans-serif and applications crash in fontconfig. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: flatpak 1.16.6-1 ProcVersionSignature: Ubuntu 7.0.0-34.34-generic 7.0.14 Uname: Linux 7.0.0-34-generic x86_64 ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: niri Date: Wed Sep 23 11:07:08 2026 InstallationDate: Installed on 2023-12-20 (1008 days ago) InstallationMedia: Ubuntu 22.04.3 LTS "Jammy Jellyfish" - Release amd64 (20230807.2) SourcePackage: flatpak UpgradeStatus: No upgrade log present (probably fresh install) modified.conffile..etc.default.apport: # set this to 0 to disable apport, or to 1 to enable it # you can temporarily override this with # sudo service apport start force_start=1 enabled=0 mtime.conffile..etc.default.apport: 2024-12-01T23:42:32.671344 ** Affects: flatpak (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug resolute wayland-session -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2168146 Title: Flatpak applications crash in fontconfig when host WOFF fonts are exposed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/flatpak/+bug/2168146/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
