This matches what I found on Kubuntu 26.04.1: the ~/.cache/fontconfig layout with .cache-12 files plus cache-9/10/11 symlinks is written by the fontconfig 2.18.3 bundled in Google Chrome 154 (the symlinks come from its compat code), and the system fontconfig 2.17.1 then reads Chrome's cache, including placeholder entries without family and charset for .woff/.woff2 files: https://gitlab.freedesktop.org/fontconfig/fontconfig/-/work_items/565. That is why a rebuild helps only until Chrome runs again.
Qt 6.10 crashes on such a fallback pattern because it does not check the result of FcPatternGetCharSet(); 0xfefefefefefefefe is the build's fill value for the uninitialized pointer. Qt fix: qtbase 80ddc8dee6a0; SRU request for qt6-base: bug 2168504. Related: bug 2168311 (with a workaround that survives Chrome runs). (Analysed with the help of an AI assistant, Claude.) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2168420 Title: libfontconfig: SIGSEGV in FcCharSetHasChar (rax=0xfefefefefefefefe) in Qt6 apps with a user font cache in ~/.cache/fontconfig To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/fontconfig/+bug/2168420/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
