Python crashes when reading some keys with os.read

The interpreter crashes when reading ^4. I know ^\ is SIGQUIT. I tested other sequences, and I didn't find anything else that crashes the interpreter. I also ran stty -a, which yielded this:

speed 38400 baud; rows 28; columns 117; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; discard = ^O; min = 1; time = 0; -parenb -parodd -cmspar cs8 -hupcl -cstopb cread -clocal -crtscts -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc -ixany -imaxbel iutf8 opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke -flusho -extproc

I'm on Python 3.14.4 on Arch Linux, kernel version 6.19.13-arch1-1.

An example:

#!/usr/bin/env -S python3 -BOO import atexit import os import select import sys import termios import tty class InpHdlr: def __init__(self) -> None: self.fd = sys.stdin.fileno() self.old_sett = termios.tcgetattr(self.fd) atexit.register(self.reset_sett) def set_new_sett(self): tty.setcbreak(self.fd) def reset_sett(self) -> None: termios.tcsetattr(self.fd, termios.TCSADRAIN, self.old_sett) def kbhit(self, timeout=0): r, _, _ = select.select([self.fd], [], [], timeout) return bool(r) def getch(self) -> str: return os.read(self.fd, 1).decode() def test(): h = InpHdlr() h.set_new_sett() k = h.getch() while h.kbhit(): k += h.getch() print(repr(k)) test()

I've tried changing os.read(...) to sys.stdin.read in the hope that it'd change the outcome, but it produced the same result.

This is the core dump I obtained:

PID: 2928085 (python3.14) UID: 1000 (vallu) GID: 983 (users) Signal: 3 (QUIT) Timestamp: Sun 2026-04-26 22:35:39 IST (59s ago) Command Line: python3.14 -BOO ./src/test.py Executable: /usr/bin/python3.14 Control Group: /user.slice/user-1000.slice/session-c1.scope Unit: session-c1.scope Slice: user-1000.slice Session: c1 Owner UID: 1000 (vallu) Boot ID: 418b7d396009454f8c6ca39c1f9d6356 Machine ID: 3bcca37ff0fa439883eb9f848307a600 Hostname: yaazh Storage: /var/lib/systemd/coredump/core.python3\x2e14.1000.418b7d396009454f8c6ca39c1f9d6356.2928085.1777223139000000.zst (present) Size on Disk: 636.7K Message: Process 2928085 (python3.14) of user 1000 dumped core. Stack trace of thread 2928085: #0 0x00007f838e4933be n/a (libc.so.6 + 0x933be) #1 0x00007f838e4933e4 n/a (libc.so.6 + 0x933e4) #2 0x00007f838e50d32e read (libc.so.6 + 0x10d32e) #3 0x00007f838ea9ab46 n/a (libpython3.14.so.1.0 + 0x29ab46) #4 0x00007f838eadb1a9 n/a (libpython3.14.so.1.0 + 0x2db1a9) #5 0x00007f838e97261d PyObject_Vectorcall (libpython3.14.so.1.0 + 0x17261d) #6 0x00007f838e986473 _PyEval_EvalFrameDefault (libpython3.14.so.1.0 + 0x186473) #7 0x00007f838e9816a5 n/a (libpython3.14.so.1.0 + 0x1816a5) #8 0x00007f838ea6f6de PyEval_EvalCode (libpython3.14.so.1.0 + 0x26f6de) #9 0x00007f838eab0301 n/a (libpython3.14.so.1.0 + 0x2b0301) #10 0x00007f838eab0e5b n/a (libpython3.14.so.1.0 + 0x2b0e5b) #11 0x00007f838eab08b7 n/a (libpython3.14.so.1.0 + 0x2b08b7) #12 0x00007f838eab0527 n/a (libpython3.14.so.1.0 + 0x2b0527) #13 0x00007f838ea61dc8 Py_RunMain (libpython3.14.so.1.0 + 0x261dc8) #14 0x00007f838ea5b52b Py_BytesMain (libpython3.14.so.1.0 + 0x25b52b) #15 0x00007f838e4276c1 n/a (libc.so.6 + 0x276c1) #16 0x00007f838e4277f9 __libc_start_main (libc.so.6 + 0x277f9) #17 0x000055909fc90045 _start (/usr/bin/python3.14 + 0x1045) ELF object binary architecture: AMD x86-64