Flatpak Eloquent repeatedly crashes bundled fastText with SIGILL (crash loop)

[DevTheFool]

Note:
This bug report was written by AI, based directly on system logs and reproduced behavior.
(Hope it helps, and don't mind the use of AI.)

---

I’m reporting a crash loop in Eloquent (Flatpak) caused by the bundled fasttext binary.

App: Eloquent (Flatpak)
App ID: re.sonny.Eloquent
OS: Linux Mint (Ubuntu-based)
Kernel: 6.8.0-90-generic
CPU: AMD Ryzen 9 3900X (x86_64, AVX/AVX2 supported)

---

What happens

When Eloquent is installed and running, it repeatedly spawns the following command inside the Flatpak sandbox:

/app/fastText/fasttext predict-prob /app/fastText/lid.176.bin - 5

The fasttext process crashes with SIGILL (Illegal instruction) and is restarted in a loop, causing continuous system crash reports.

---

Important clarification (Flatpak sandbox)

The path /app/fastText/fasttext exists only inside the Flatpak sandbox, not on the host system.

Verified behavior:

• On host system:

  /app/fastText/fasttext → No such file or directory
  

• Inside Flatpak sandbox:

  flatpak run --command=sh re.sonny.Eloquent
  ls /app/fastText
  → fasttext, lid.176.bin, etc.
  

This confirms the crashing binary is the one bundled with the Eloquent Flatpak.

---

Evidence (coredump)

From coredumpctl info:

• Executable: /app/fastText/fasttext
• Signal: SIGILL (4)
• Command line:
  /app/fastText/fasttext predict-prob /app/fastText/lid.176.bin - 5
• CGroup / scope:
  app-flatpak-re.sonny.Eloquent-XXXX.scope

This directly ties the crash to the Eloquent Flatpak.

---

Expected behavior

If language detection fails, Eloquent should fail gracefully and not enter a crash/restart loop.

---

Notes

SIGILL typically indicates that the binary is using CPU instructions that are not valid at runtime, or that the bundled fasttext binary is otherwise incompatible. This may be a Flatpak packaging or build configuration issue with the included fastText binary.

---

(base) dev@dev-desktop:~$ flatpak info re.sonny.Eloquent

Eloquent - Your proofreading assistant

          ID: re.sonny.Eloquent
         Ref: app/re.sonny.Eloquent/x86_64/stable
        Arch: x86_64
      Branch: stable
     Version: 1.4
     License: GPL-3.0
      Origin: flathub
  Collection: org.flathub.Stable
Installation: system
   Installed: 747,5 MB
     Runtime: org.gnome.Platform/x86_64/49
         Sdk: org.gnome.Sdk/x86_64/49

      Commit: 3ba7be5c1882a538bf7efdc1d4cca978edad169232a637ca8bcde16da3fa141f
      Parent: cd6f474c18c2350d783628e0d0a4ced38fdbc23a9300ab10a3174a75711fb055
     Subject: v1.4 (#8) (9c29bba7e427)
        Date: 2025-12-05 21:25:04 +0000
(base) dev@dev-desktop:~$ flatpak info --show-runtime re.sonny.Eloquent
org.gnome.Platform/x86_64/49
(base) dev@dev-desktop:~$ flatpak info --show-permissions re.sonny.Eloquent
[Context]
shared=network;ipc;
sockets=x11;wayland;fallback-x11;
devices=dri;

[Environment]
PATH=/app/jre/bin:/usr/bin:/app/bin
(base) dev@dev-desktop:~$ coredumpctl info --no-pager | sed -n '1,80p'
           PID: 31709 (fasttext)
           UID: 1000 (dev)
           GID: 1000 (dev)
        Signal: 4 (ILL)
     Timestamp: Sun 2026-01-18 22:29:50 EET (1min 30s ago)
  Command Line: /app/fastText/fasttext predict-prob /app/fastText/lid.176.bin - 5
    Executable: /app/fastText/fasttext
 Control Group: /user.slice/user-1000.slice/user@1000.service/app.slice/app-flatpak-re.sonny.Eloquent-2313.scope
          Unit: user@1000.service
     User Unit: app-flatpak-re.sonny.Eloquent-2313.scope
         Slice: user-1000.slice
     Owner UID: 1000 (dev)
       Boot ID: cf140a7fe1d747edb853442135bd51aa
    Machine ID: 1e4e078b385c404db6d635a7f4931697
      Hostname: dev-desktop
       Storage: /var/lib/systemd/coredump/core.fasttext.1000.cf140a7fe1d747edb853442135bd51aa.31709.1768768190000000.zst (present)
  Size on Disk: 2.6M
       Message: Process 31709 (fasttext) of user 1000 dumped core.
                
                Stack trace of thread 351:
                #0  0x0000566756d7d44a n/a (/app/fastText/fasttext + 0xc44a)
                #1  0x00007aa30c72d975 n/a (/usr/lib/x86_64-linux-gnu/libc.so.6 + 0x2b975)
                #2  0x00007aa30c72da28 n/a (/usr/lib/x86_64-linux-gnu/libc.so.6 + 0x2ba28)
                #3  0x0000566756d7da95 n/a (/app/fastText/fasttext + 0xca95)
                ELF object binary architecture: AMD x86-64
(base) dev@dev-desktop:~$ lscpu | grep -i flags
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 mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid aperfmperf rapl pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate ssbd mba ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 cqm rdt_a rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local clzero irperf xsaveerptr rdpru wbnoinvd arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmload vgif v_spec_ctrl umip rdpid overflow_recov succor smca sev sev_es ibpb_exit_to_user
(base) dev@dev-desktop:~$ uname -a
Linux dev-desktop 6.8.0-90-generic #91-Ubuntu SMP PREEMPT_DYNAMIC Tue Nov 18 14:14:30 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux
(base) dev@dev-desktop:~$ flatpak run --command=sh re.sonny.Eloquent -c "file /app/fastText/fasttext"
/app/fastText/fasttext: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=dd8c87ec04a418d8a164c8b4828f5523b6657e25, for GNU/Linux 3.2.0, stripped

[rodrigocaus]

I have the same problem with Eloquent in Flatkpak runtime, however in a different setup:

App: Eloquent (Flatpak)
App ID: re.sonny.Eloquent
OS: Fedora Workstation 43
Kernel: 6.18.7-200.fc43.x86_64
CPU: Intel i5-13600K (x86_64, AVX/AVX2 supported)

This problem happens to me on every PC startup.

[artem-korolev]

same problem. every PC start.

chatgpt saying fasttext expects AVX512, which is missing in my CPU

$ flatpak info re.sonny.Eloquent | sed -n '1,80p'

Eloquent - Your proofreading assistant

          ID: re.sonny.Eloquent
         Ref: app/re.sonny.Eloquent/x86_64/stable
        Arch: x86_64
      Branch: stable
     Version: 1.4
     License: GPL-3.0
      Origin: flathub
  Collection: org.flathub.Stable
Installation: system
   Installed: 747.5 MB
     Runtime: org.gnome.Platform/x86_64/49
         Sdk: org.gnome.Sdk/x86_64/49

      Commit: 3ba7be5c1882a538bf7efdc1d4cca978edad169232a637ca8bcde16da3fa141f
      Parent: cd6f474c18c2350d783628e0d0a4ced38fdbc23a9300ab10a3174a75711fb055
     Subject: v1.4 (#8) (9c29bba7e427)
        Date: 2025-12-05 21:25:04 +0000

$ flatpak run --command=sh re.sonny.Eloquent
[📦 re.sonny.Eloquent ~]$ /app/fastText/fasttext -h
Illegal instruction        (core dumped) /app/fastText/fasttext -h


$ lscpu | sed -n '1,25p'
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):                                  12
On-line CPU(s) list:                     0-11
Vendor ID:                               GenuineIntel
Model name:                              Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
CPU family:                              6
Model:                                   158
Thread(s) per core:                      2
Core(s) per socket:                      6
Socket(s):                               1
Stepping:                                10
CPU(s) scaling MHz:                      57%
CPU max MHz:                             4500.0000
CPU min MHz:                             800.0000
BogoMIPS:                                5199.98
Flags:                                   fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch cpuid_fault epb pti ssbd ibrs ibpb stibp tpr_shadow flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx rdseed adx smap clflushopt intel_pt xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp vnmi md_clear flush_l1d arch_capabilities
Virtualization:                          VT-x
L1d cache:                               192 KiB (6 instances)
L1i cache:                               192 KiB (6 instances)
L2 cache:                                1.5 MiB (6 instances)
L3 cache:                                12 MiB (1 instance)
NUMA node(s):                            1

[ETH1166]

Dear Sonny @sonnyp

Thank you for this great tool!
But the same happens to me using Fedora Workstation 43.

[📦 re.sonny.Eloquent ~]$ /app/fastText/fasttext -h
Ungültiger Maschinenbefehl(Speicherabzug geschrieben) /app/fastText/fasttext -h
[📦 re.sonny.Eloquent ~]$ 

I am using the latest Version from Flathub: V1.4

Please let me know if I can assist with anything.

Thank you in advance for any improvements.

Best regards
Thomas

[genodeftest]

See also the report on the github repo for the flathub package: flathub/re.sonny.Eloquent#10

[genodeftest]

May be related: facebookresearch/fastText#457

[Pashoupati]

same problem fedora 43 gnome edition

[genodeftest]

Following the steps for debugging flatpak applications according to flatpak docs, I followed these steps:

1. I installed debug symbols for the flatpak app using flatpak install --include-sdk --include-debug re.sonny.Eloquent
2. I executed $ flatpak run --command=sh --devel --filesystem=$(pwd) re.sonny.Eloquent to enter a debug shell in the flatpak app's environment
3. I tried executing the app itself under gdb, which doesn't work that easily, because it is JavaScript code run in an interpreter, that executes a Java runtime, which executes fasttext later.
4. I executed the app under strace to understand how fasttext is being executed: strace --string-limit=256 --no-abbrev --trace=%process --follow-forks /app/bin/re.sonny.Eloquent 2> eloquent.strace.log
5. In the strace log from the previous step, I searched for fasttext and found the lines in which the fasttext is invoked:

   [pid   320] execve("/app/fastText/fasttext", ["/app/fastText/fasttext", "predict-prob", "/app/fastText/lid.176.bin", "-", "5"], […]) = 0
   [pid   320] --- SIGILL {si_signo=SIGILL, si_code=ILL_ILLOPN, si_addr=0x55cf8ee3244a} ---
   […]
   [pid   321] wait4(320 <unfinished ...>
   […]
   [pid   320] +++ killed by SIGILL (core dumped) +++
   [pid   321] <... wait4 resumed>, [{WIFSIGNALED(s) && WTERMSIG(s) == SIGILL && WCOREDUMP(s)}], 0, NULL) = 320
   [pid   325] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_DUMPED, si_pid=320, si_uid=1000, si_status=SIGILL, si_utime=0, si_stime=0} ---
   

6. Trying to replicate the crash, I started gdb with gdb /app/fastText/fasttext, then started the application with run predict-prob /app/fastText/lid.176.bin
7. gdb immediately came to a halt (running into the SIGILL).
8. In gdb, execute layout asm, which shows that the process stopped at CPU instruction vpbroadcastq

The vpbroadcastq instruction requires CPU flag avx2 according to this docs, but my CPU doesn't have it, according to lscpu | grep Flags. As described in the upstream bug report facebookresearch/fastText#457, this is a result of compiling the binary against the wrong CPU architecture, i.e., fasttext compiles with -march=native by default, which makes the executable only run on CPUs at least as modern as the CPU the binary was built on.

Note: With debug symbols missing (because something went wrong in the flatpak generation), there is not a lot of info on the executable.

[genodeftest]

The problem that's happening here is that during building this flatpak app, the build process is downloading precompiled binaries instead of compiling them properly for the relevant target architecture(s).

Has anyone seen this issue with a different distribution than the flatpak app? I would expect no, and therefore claim that this is a packaging issue of the flatpak app.

[sonnyp]

Thanks for the details. This doesn't solve it cec258a ?\

Otherwise PR welcome https://github.com/sonnyp/Eloquent/blob/main/re.sonny.Eloquent.json (Flathub inherits this manifest)

[genodeftest]

From theory, this looks good, as it includes the source instead of a pre-built binary as far as I can see.

Is there a new flatpak build from your last git commit? (A development build would be sufficient)

[bellegarde-c]

Thanks for the details. This doesn't solve it cec258a ?\

Otherwise PR welcome https://github.com/sonnyp/Eloquent/blob/main/re.sonny.Eloquent.json (Flathub inherits this manifest)

Indeed, I was wrong, the fix is not about version but about build:

[~/Téléchargements/fastText-0.9.2]$ sudo cp fasttext /var/lib/flatpak/app/re.sonny.Eloquent/current/active/files/fastText/fasttext

And it does not segfault anymore...

[orgcontrib]

Uninstalled, but here I am, reconfirming the issue:

dacbarbos@vivobookone:~$ flatpak info re.sonny.Eloquent

Eloquent - Your proofreading assistant

            ID: re.sonny.Eloquent
           Ref: app/re.sonny.Eloquent/x86_64/stable
          Arch: x86_64
        Branch: stable
       Version: 1.4
       License: GPL-3.0
        Origin: flathub
    Collection: org.flathub.Stable
  Installation: system
Installed Size: 747.5 MB
       Runtime: org.gnome.Platform/x86_64/49
           Sdk: org.gnome.Sdk/x86_64/49

        Commit: 3ba7be5c1882a538bf7efdc1d4cca978edad169232a637ca8bcde16da3fa141f
        Parent: cd6f474c18c2350d783628e0d0a4ced38fdbc23a9300ab10a3174a75711fb055
       Subject: v1.4 (#8) (9c29bba7e427)
          Date: 2025-12-05 21:25:04 +0000
dacbarbos@vivobookone:~$ 
dacbarbos@vivobookone:~$ coredumpctl -1
TIME                          PID  UID  GID SIG    COREFILE EXE                    SIZE
Wed 2026-04-29 17:38:50 EEST 5436 1000 1000 SIGILL present  /app/fastText/fasttext 2.6M
dacbarbos@vivobookone:~$ 
dacbarbos@vivobookone:~$ coredumpctl info 5436
           PID: 5436 (fasttext)
           UID: 1000 (dacbarbos)
           GID: 1000 (dacbarbos)
        Signal: 4 (ILL)
     Timestamp: Wed 2026-04-29 17:38:49 EEST (1h 3min ago)
  Command Line: /app/fastText/fasttext predict-prob /app/fastText/lid.176.bin - 5
    Executable: /app/fastText/fasttext
 Control Group: /user.slice/user-1000.slice/user@1000.service/app.slice/app-flatpak-re.sonny.Eloquent-2256949927.scope
          Unit: user@1000.service
     User Unit: app-flatpak-re.sonny.Eloquent-2256949927.scope
         Slice: user-1000.slice
     Owner UID: 1000 (dacbarbos)
       Boot ID: 939d67b65ef848caa380e6869fe0e142
    Machine ID: 1fa1d932ed2f42f382d4a8455c1cb58e
      Hostname: vivobookone.internal
       Storage: /var/lib/systemd/coredump/core.fasttext.1000.939d67b65ef848caa380e6869fe0e142.5436.1777473529000000.zst (present)
  Size on Disk: 2.6M
       Message: Process 5436 (fasttext) of user 1000 dumped core.
                
                Stack trace of thread 47:
                #0  0x0000557d47ee344a n/a (/app/fastText/fasttext + 0xc44a)
                #1  0x00007f3d65f2d975 n/a (/usr/lib/x86_64-linux-gnu/libc.so.6 + 0x2b975)
                #2  0x00007f3d65f2da28 n/a (/usr/lib/x86_64-linux-gnu/libc.so.6 + 0x2ba28)
                #3  0x0000557d47ee3a95 n/a (/app/fastText/fasttext + 0xca95)
                ELF object binary architecture: AMD x86-64
dacbarbos@vivobookone:~$ 
dacbarbos@vivobookone:~$ hostnamectl
     Static hostname: vivobookone.internal
           Icon name: computer-laptop
             Chassis: laptop 💻
   Chassis Asset Tag: DACBARBOS
          Deployment: development
            Location: Romania, non-fixed (movable)
          Machine ID: 1fa1d932ed2f42f382d4a8455c1cb58e
             Boot ID: 939d67b65ef848caa380e6869fe0e142
    Operating System: Fedora Linux 44 (Workstation Edition)
         CPE OS Name: cpe:/o:fedoraproject:fedora:44
      OS Support End: Wed 2027-05-19
OS Support Remaining: 1y 2w 5d                             
              Kernel: Linux 6.19.14-300.fc44.x86_64
        Architecture: x86-64
     Hardware Vendor: ASUSTeK COMPUTER INC.
      Hardware Model: VivoBook_ASUS Laptop X505ZA_X505ZA
    Hardware Version: 1.0
    Firmware Version: X505ZA.313
       Firmware Date: Tue 2020-02-25
        Firmware Age: 6y 2month 3d                         
dacbarbos@vivobookone:~$ 

[tingweiwan]

Yes. This bug still exists.

[MMYoung57]

Same issue. Fedora 44 KDE
PID: 6840 (fasttext)
UID: 1000 (mark)
GID: 1000 (mark)
Signal: 4 (ILL)
Timestamp: Tue 2026-05-26 13:00:55 CDT (6s ago)
Command Line: /app/fastText/fasttext predict-prob /app/fastText/lid.176.bin - 5
Executable: /app/fastText/fasttext
Control Group: /user.slice/user-1000.slice/user@1000.service/app.slice/app-flatpak-re.sonny.Eloquent-1163218206.scope
Unit: user@1000.service
User Unit: app-flatpak-re.sonny.Eloquent-1163218206.scope
Slice: user-1000.slice
Owner UID: 1000 (mark)
Boot ID: 56e2b596e31d47c1be493beb7a36fda7
Machine ID: 4cbb2423d68846ca839be07d71ff96f0
Hostname: HomePC
Storage: /var/lib/systemd/coredump/core.fasttext.1000.56e2b596e31d47c1be493beb7a36fda7.6840.1779818455000000.zst (present)
Size on Disk: 2.6M
Message: Process 6840 (fasttext) of user 1000 dumped core.

            Stack trace of thread 55:
            #0  0x000055d28b6cc44a n/a (/app/fastText/fasttext + 0xc44a)
            #1  0x00007faab0d2d975 n/a (/usr/lib/x86_64-linux-gnu/libc.so.6 + 0x2b975)
            #2  0x00007faab0d2da28 n/a (/usr/lib/x86_64-linux-gnu/libc.so.6 + 0x2ba28)
            #3  0x000055d28b6cca95 n/a (/app/fastText/fasttext + 0xca95)
            ELF object binary architecture: AMD x86-64

Just an FYI - this doesn't happen when Eloquent is installed on Debian 13.5 and KDE.