pkg/59720: curl hangs or crashes with pthread_cancel enabled

["T K Spindler (moof)" <dogcow%babymeat.com@localhost>]

>Number:         59720
>Category:       pkg
>Synopsis:       curl hangs or crashes with pthread_cancel enabled
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Oct 24 01:25:00 +0000 2025
>Originator:     dogcow%babymeat.com@localhost
>Release:        NetBSD 11.0_BETA
>Organization:

>Environment:


System: NetBSD flippy.babymeat.com 11.0_BETA NetBSD 11.0_BETA (FLIPPY) #8: Mon Oct 20 22:34:18 CDT 2025 dogcow%flippy.babymeat.com@localhost:/crap/obj/hg11obj/src/hg/11src/sys/arch/amd64/compile/FLIPPY amd64
Architecture: x86_64
Machine: amd64
>Description:
curl 8.16.0 enables use of pthread_cancel in resolver threads; this can
cause hangs and/or coredumps.

see also: https://github.com/curl/curl/issues/18532 and
https://eissing.org/icing/posts/rip_pthread_cancel/ (or the chatter on
ICB on the topic)
>How-To-Repeat:

install curl 8.16.0, run something that uses pthreads and DNS resolution;
it may eventually hit 100%/hang, and/or crash. (In my case, lwp_park and 100%
cpu utilization)
>Fix:

either unconditionally disable pthread_cancel (see
https://github.com/curl/curl/blob/curl-8_16_0/lib/curl_threads.c#L103-L129
for where it's done for FreeBSD), revert to an older version of curl, or
wait for some post-8.16 curl version. This may need to get pulled up to
pkgsrc-2025Q3 (which uses 8.16.)


>Unformatted: