From: Percy Piper Subject: Pandas datetime parsing segfaults on current amd64 snaps. To: ports@openbsd.org Date: Wed, 23 Sep 2026 13:19:28 +0100 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 deraadt@amd64.openbsd.org:/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() 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 deraadt@amd64.openbsd.org:/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 ecx=f6da3203 cpu0: cpuid 7.0 ebx=1c2fb9 edx=400 cpu0: cpuid d.1 eax=1 cpu0: cpuid 80000001 edx=2c100800 ecx=121 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: 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: 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: 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: 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