2.54.0-rc1 NO_WRITEV=Nope does not work

[<rsbecker@nexbridge.com>]

With a completely clean build, we are getting writev() being used anyway on
NonStop:

/usr/coreutils/bin/make NO_TCLTK=NoThanks NO_WRITEV=Nope V=1
prefix=/usr/local-ssl3.5 CFLAGS=-g -O2 -D_LARGEFILE64_SOURCE=1
-D_FILE_OFFSET_BITS=64 -Winline -I/usr/local-ssl3.5/include
-I/usr/coreutils/include -I/usr/tandem/xml/T0625L01_AAE/include
LDFLAGS=-D_LARGEFILE64_SOURCE=1 -D_FILE_OFFSET_BITS=64
/usr/coreutils/lib/libz.a -L/usr/local-ssl3.5/lib -L/usr/coreutils/lib
-L/usr/tandem/xml/T0625L01_AAE/lib SHELL=/usr/coreutils/bin/bash
GIT_VERSION=2.54.0.rc1

Down to the first instance:

Cloning into bare repository 'clone.git'...
remote: Enumerating objects: 629, done.
fatal: writev error: Invalid function argument
fetch-pack: unexpected disconnect while reading sideband packet
fatal: early EOF
fatal: fetch-pack: invalid index-pack output
not ok 25 - clone from bitmapped repository
#
#                       rm -fr clone.git &&
#                       git clone --no-local --bare . clone.git &&
#                       git rev-parse HEAD >expect &&
#                       git --git-dir=clone.git rev-parse HEAD >actual &&
#                       test_cmp expect actual
#

Did I mess this up?

--
Brief whoami: NonStop&UNIX developer since approximately
UNIX(421664400)
NonStop(211288444200000000)
-- In real life, I talk too much.