https://bugs.kde.org/show_bug.cgi?id=444545
--- Comment #7 from Peter Hull <peterhul...@gmail.com> --- As I'm using VirtualBox I can restart the VM with AVX2 disabled, using the command .\vboxmanage setextradata "Fedora" VBoxInternal/CPUM/IsaExts/AVX2 0 Now the problem does not occur. However, I did report in comment 2 that under Debian the problem didn't occur either, and this was using the same VirtualBox/Host PC, so it isn't simply AVX2 vs not AVX2. Thanks for your help so far! The output of lscpu in this case is $ lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Address sizes: 39 bits physical, 48 bits virtual Byte Order: Little Endian CPU(s): 1 On-line CPU(s) list: 0 Vendor ID: GenuineIntel Model name: Intel(R) Core(TM) i7-8750H CPU @ 2.20GHz CPU family: 6 Model: 158 Thread(s) per core: 1 Core(s) per socket: 1 Socket(s): 1 Stepping: 10 BogoMIPS: 4415.99 Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx rdtscp lm constant_tsc rep_good nopl xtopology nonstop_tsc cpuid tsc_known_freq pni pclmulqdq monitor ssse3 cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx rdrand hypervisor lahf_lm abm 3dnowpre fetch invpcid_single pti fsgsbase invpcid rdseed clflushopt md_clear flush_l1d Virtualization features: Hypervisor vendor: KVM Virtualization type: full Caches (sum of all): L1d: 32 KiB (1 instance) L1i: 32 KiB (1 instance) L2: 256 KiB (1 instance) L3: 9 MiB (1 instance) NUMA: NUMA node(s): 1 NUMA node0 CPU(s): 0 Vulnerabilities: Itlb multihit: KVM: Mitigation: VMX unsupported L1tf: Mitigation; PTE Inversion Mds: Mitigation; Clear CPU buffers; SMT Host state unknown Meltdown: Mitigation; PTI Spec store bypass: Vulnerable Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer sanitization Spectre v2: Mitigation; Full generic retpoline, STIBP disabled, RSB filling Srbds: Unknown: Dependent on hypervisor status Tsx async abort: Not affected -- You are receiving this mail because: You are watching all bug changes.