Since updating one of my amd64 machines from 7.9 to current
all attempts to parse datetimes in pandas lead to a segfault.
I can reproduce on a test vm running today's snapshot:
Install a recent amd64 snapshot
pkg_add python pandas
$ sysctl kern.version
kern.version=OpenBSD 8.0-beta (GENERIC.MP) #54: Wed Sep 23 01:05:05 MDT 2026
[email protected]:/usr/src/sys/arch/amd64/compile/GENERIC.MP
pkg_info -m
intel-firmware-20260812v0 microcode update binaries for Intel CPUs
py3-pandas-2.3.3 data analysis and manipulation library
python-3.14.6p0 interpreted object-oriented programming language
quirks-7.225 exceptions to pkg_add rules
$ python3
Python 3.14.6 (main, Sep 11 2026, 17:37:25) [Clang 22.1.6 ] on openbsd8
Type "help", "copyright", "credits" or "license" for more information.
import pandas as pd
pd.to_datetime(['2026-09-23 12:00'])
Segmentation fault (core dumped)
Specifying the format or using 'coerce' does not affect the outcome:
pd.to_datetime(['2026-09-23 01:00'], format='%Y-%m-%d %H:%M', errors='coerce')
Segmentation fault (core dumped)
Attempts to parse dates with pd.import_csv() are also affected:
$ printf '"Date","Name"\n"2026-09-23","Test"\n' > test.csv
$ python3
Python 3.14.6 (main, Sep 21 2026, 17:01:36) [Clang 22.1.6 ] on openbsd8
Type "help", "copyright", "credits" or "license" for more information.
import pandas as pd
df = pd.read_csv('test.csv')
df.info()
<class 'pandas.core.frame.DataFrame'>
RangeIndex: 1 entries, 0 to 0
Data columns (total 2 columns):
# Column Non-Null Count Dtype
--- ------ -------------- -----
0 Date 1 non-null object
1 Name 1 non-null object
dtypes: object(2)
memory usage: 148.0+ bytes
df2 = pd.read_csv('test.csv', parse_dates=['Date'])
Segmentation fault (core dumped)
Percy.
OpenBSD 8.0-beta (GENERIC.MP) #54: Wed Sep 23 01:05:05 MDT 2026
[email protected]:/usr/src/sys/arch/amd64/compile/GENERIC.MP
real mem = 4278124544 (4079MB)
avail mem = 4126486528 (3935MB)
random: good seed from bootblocks
mpath0 at root
scsibus0 at mpath0: 256 targets
mainbus0 at root
bios0 at mainbus0: SMBIOS rev. 2.3 @ 0xf93e0 (338 entries)
bios0: vendor American Megatrends Inc. version "090008" date 02/27/2023
bios0: Microsoft Corporation Virtual Machine
acpi0 at bios0: ACPI 2.0
acpi0: sleep states S0 S5
acpi0: tables DSDT FACP WAET SLIC OEM0 SRAT APIC OEMB
acpi0: wakeup devices
acpitimer0 at acpi0: 3579545 Hz, 32 bits
acpihve0 at acpi0
acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
ioapic0 at mainbus0: apid 0 pa 0xfec00000, version 11, 24 pins, remapped
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: Intel(R) Xeon(R) CPU E5-2673 v4 @ 2.30GHz, 2294.76 MHz, 06-4f-01
cpu0: cpuid 1
edx=1f8bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2,SS,HTT>
ecx=f6da3203<SSE3,PCLMUL,SSSE3,FMA3,CX16,PCID,SSE4.1,SSE4.2,MOVBE,POPCNT,AES,XSAVE,AVX,F16C,RDRAND,HV>
cpu0: cpuid 7.0
ebx=1c2fb9<FSGSBASE,BMI1,HLE,AVX2,SMEP,BMI2,ERMS,INVPCID,RTM,RDSEED,ADX,SMAP>
edx=400<MD_CLEAR>
cpu0: cpuid d.1 eax=1<XSAVEOPT>
cpu0: cpuid 80000001 edx=2c100800<NXE,PAGE1GB,RDTSCP,LONG>
ecx=121<LAHF,ABM,3DNOWP>
cpu0: MELTDOWN
cpu0: 32KB 64b/line 8-way D-cache, 32KB 64b/line 8-way I-cache, 256KB 64b/line
8-way L2 cache, 50MB 64b/line 20-way L3 cache
cpu0: smt 0, core 0, package 0, type P
mtrr: Pentium Pro MTRR support, 8 var ranges, 88 fixed ranges
cpu0: apic clock running at 200MHz
cpu1 at mainbus0: apid 1 (application processor)
cpu1: Intel(R) Xeon(R) CPU E5-2673 v4 @ 2.30GHz, 2294.72 MHz, 06-4f-01
cpu1: smt 0, core 1, package 0, type P
acpiprt0 at acpi0: bus 0 (PCI0)
acpipci0 at acpi0 PCI0
acpicmos0 at acpi0
"PNP0303" at acpi0 not configured
"PNP0F03" at acpi0 not configured
com0 at acpi0 UAR1 addr 0x3f8/0x8 irq 4: ns16550a, 16 byte fifo
com0: console
com1 at acpi0 UAR2 addr 0x2f8/0x8 irq 3: ns16550a, 16 byte fifo
"VMBus" at acpi0 not configured
"Hyper_V_Gen_Counter_V1" at acpi0 not configured
acpicpu0 at acpi0: C1(@1 halt!)
acpicpu1 at acpi0: C1(@1 halt!)
cpu0: using VERW MDS workaround
pvbus0 at mainbus0: Hyper-V 10.0
hyperv0 at pvbus0: protocol 4.0, features 0x2e7f
hyperv0: heartbeat, kvp, shutdown, timesync
hvs0 at hyperv0 channel 3: ide, protocol 6.2
scsibus1 at hvs0: 2 targets
sd0 at scsibus1 targ 0 lun 0: <Msft, Virtual Disk, 1.0>
naa.60022480f8af289154d3b9dd5a788594
sd0: 20481MB, 512 bytes/sector, 41945088 sectors, thin
hvs1 at hyperv0 channel 4: ide, protocol 6.2
scsibus2 at hvs1: 2 targets
sd1 at scsibus2 targ 1 lun 0: <Msft, Virtual Disk, 1.0>
naa.600224808d69b90a84620e47ebe722a9
sd1: 8192MB, 512 bytes/sector, 16777216 sectors, thin
hvs2 at hyperv0 channel 14: scsi, protocol 6.2
scsibus3 at hvs2: 2 targets
hvs3 at hyperv0 channel 15: scsi, protocol 6.2
scsibus4 at hvs3: 2 targets
sd2 at scsibus4 targ 0 lun 0: <Msft, Virtual Disk, 1.0>
naa.6002248071f859a9a569c7c391eb0e90
sd2: 1048576MB, 512 bytes/sector, 2147483648 sectors, thin
hvn0 at hyperv0 channel 13: NVS 5.0 NDIS 6.30, address 7c:ed:8d:49:6a:40
pci0 at mainbus0 bus 0
pchb0 at pci0 dev 0 function 0 "Intel 82443BX" rev 0x03
pcib0 at pci0 dev 7 function 0 "Intel 82371AB PIIX4 ISA" rev 0x01
pciide0 at pci0 dev 7 function 1 "Intel 82371AB IDE" rev 0x01: DMA, channel 0
wired to compatibility, channel 1 wired to compatibility
pciide0: channel 0 disabled (no drives)
atapiscsi0 at pciide0 channel 1 drive 0
scsibus5 at atapiscsi0: 2 targets
cd0 at scsibus5 targ 0 lun 0: <Msft, Virtual CD/ROM, 1.0> removable
cd0(pciide0:1:0): using PIO mode 4, DMA mode 2
piixpm0 at pci0 dev 7 function 3 "Intel 82371AB Power" rev 0x02: SMBus disabled
vga1 at pci0 dev 8 function 0 "Microsoft VGA" rev 0x00
wsdisplay at vga1 not configured
isa0 at pcib0
isadma0 at isa0
fdc0 at isa0 port 0x3f0/6 irq 6 drq 2
pckbc0 at isa0 port 0x60/5 irq 1 irq 12
pckbd0 at pckbc0 (kbd slot)
wskbd0 at pckbd0 mux 1
pms0 at pckbc0 (aux slot)
wsmouse0 at pms0 mux 0
pcppi0 at isa0 port 0x61
spkr0 at pcppi0
hvn0: restrict all mbufs to low memory
vscsi0 at root
scsibus6 at vscsi0: 256 targets
softraid0 at root
scsibus7 at softraid0: 256 targets
root on sd0a (7d4563364fb3c44a.a) swap on sd0b dump on sd0b
fd0 at fdc0 drive 0: 1.44MB 80 cyl, 2 head, 18 sec
fd1 at fdc0 drive 1: density unknown
acpi0: PM1 stuck (en 0x101 st 0x1), clearing
