glib-2.78.0 fails at gio/tests/gsubprocess.p/gsubprocess.c.o
I see the following error when executing ninja in glib-2.78.0 builddir
$ ninja [1/2] Compiling C object gio/tests/gsubprocess.p/gsubprocess.c.o
FAILED: gio/tests/gsubprocess.p/gsubprocess.c.o
cc -Igio/tests/gsubprocess.p -Igio/tests -I../gio/tests -I. -I.. -Iglib -I../glib -Igmodule -I../gmodule -Igobject -I../gobject -Igio -I../gio -fdiagnostics-color=always -D_FILE_OFFSET_BITS=64 -Wall -Winvalid-pch -Wextra -Wpedantic -std=gnu99 -O2 -g -D_GNU_SOURCE -fno-strict-aliasing -DG_DISABLE_CAST_CHECKS -Wduplicated-branches -Wimplicit-fallthrough -Wmisleading-indentation -Wmissing-field-initializers -Wnonnull -Wunused -Wno-unused-parameter -Wno-cast-function-type -Wno-pedantic -Wno-format-zero-length -Wno-variadic-macros -Werror=format=2 -Werror=init-self -Werror=missing-include-dirs -Werror=pointer-arith -Werror=unused-result -Wstrict-prototypes -Wno-bad-function-cast -Werror=implicit-function-declaration -Werror=missing-prototypes -Werror=pointer-sign '-DG_LOG_DOMAIN="GLib-GIO"' '-DGLIB_MKENUMS="gobject/glib-mkenums"' '-DGLIB_COMPILE_SCHEMAS="/eph/build/glib/glib-2.78.0/builddir/gio/glib-compile-schemas"' -UG_DISABLE_ASSERT -DHAVE_OPENPTY -MD -MQ gio/tests/gsubprocess.p/gsubprocess.c.o -MF gio/tests/gsubprocess.p/gsubprocess.c.o.d -o gio/tests/gsubprocess.p/gsubprocess.c.o -c ../gio/tests/gsubprocess.c
In file included from ../glib/glib.h:89,
from ../gobject/gbinding.h:30,
from ../glib/glib-object.h:24,
from ../gio/gioenums.h:30,
from ../gio/giotypes.h:30,
from ../gio/gio.h:28,
from ../gio/tests/gsubprocess.c:1:
../gio/tests/gsubprocess.c: In function ‘trace_children’:
../gio/tests/gsubprocess.c:2009:31: error: ‘PTRACE_O_EXITKILL’ undeclared (first use in this function); did you mean ‘PTRACE_KILL’?
2009 | PTRACE_O_EXITKILL |
| ^~~~~~~~~~~~~~~~~
../glib/gtestutils.h:206:54: note: in definition of macro ‘g_assert_no_errno’
206 | __ret = expr; \
| ^~~~
../gio/tests/gsubprocess.c:2009:31: note: each undeclared identifier is reported only once for each function it appears in
2009 | PTRACE_O_EXITKILL |
| ^~~~~~~~~~~~~~~~~
../glib/gtestutils.h:206:54: note: in definition of macro ‘g_assert_no_errno’
206 | __ret = expr; \
| ^~~~
ninja: build stopped: subcommand failed.
Any idea what might cause this and how to fix it?