If have searched for GLIBCPIE within all meta-files, but it seems that GLIBCPIE is already empty.

varga-r@ubuntu:~/projects/yocto-tq-mba6x$ grep -rnI "GLIBCPIE"
poky/meta/conf/distro/include/security_flags.inc:9:# If static PIE is known to work well, GLIBCPIE="--enable-static-pie" can be set
poky/meta/conf/distro/include/security_flags.inc:34:GLIBCPIE_powerpc = ""
poky/meta/recipes-core/glibc/glibc_2.29.bb:73:GLIBCPIE ??= ""
poky/meta/recipes-core/glibc/glibc_2.29.bb:89:                ${GLIBCPIE} \

Then I searched for "pie" within the generated glibc sources... and found many search results including " *-pie* " or " *-fpie* " as passed compiler parameter for various files (note that I pasted two lines only!):
varga-r@ubuntu:~/projects/yocto-tq-mba6x$ grep -rnI "pie" build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc
<snip>
...
build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/temp/log.do_compile.90521:10133:arm-poky-linux-gnueabi-gcc  -mthumb -mfpu=neon -mfloat-abi=hard -mcpu=cortex-a9  --sysroot=/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/recipe-sysroot *-pie* -Wl,-O1 -nostdlib -nostartfiles -o /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/iconv/iconvconfig  -fuse-ld=bfd  -Wl,-z,combreloc -Wl,-z,relro -Wl,--hash-style=both /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/csu/Scrt1.o /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/csu/crti.o `arm-poky-linux-gnueabi-gcc  -mthumb -mfpu=neon -mfloat-abi=hard -mcpu=cortex-a9  --sysroot=/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/recipe-sysroot  --print-file-name=crtbeginS.o` /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/iconv/iconvconfig.o /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/iconv/strtab.o /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/iconv/xmalloc.o /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/iconv/hash-string.o  -Wl,-dynamic-linker=/lib/ld-linux-armhf.so.3 -Wl,-rpath-link=/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi:/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/math:/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/elf:/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/dlfcn:/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/nss:/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/nis:/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/rt:/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/resolv:/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/mathvec:/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/support:/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/nptl /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/libc.so.6 /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/libc_nonshared.a -Wl,--as-needed /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/elf/ld.so -Wl,--no-as-needed -lgcc /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/elf/libgcc-stubs.a `arm-poky-linux-gnueabi-gcc  -mthumb -mfpu=neon -mfloat-abi=hard -mcpu=cortex-a9  --sysroot=/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/recipe-sysroot  --print-file-name=crtendS.o` /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/csu/crtn.o
...
build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/temp/log.do_compile.90521:14335:arm-poky-linux-gnueabi-gcc  -mthumb -mfpu=neon -mfloat-abi=hard -mcpu=cortex-a9  --sysroot=/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/recipe-sysroot res_hconf.c -c -std=gnu11 -fgnu89-inline  -O2 -pipe -feliminate-unused-debug-types -fmacro-prefix-map=/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0=/usr/src/debug/glibc/2.29-r0 -fdebug-prefix-map=/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0=/usr/src/debug/glibc/2.29-r0 -fdebug-prefix-map=/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/recipe-sysroot= -fdebug-prefix-map=/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/recipe-sysroot-native= -Wall -Wwrite-strings -Wundef -Werror -fmerge-all-constants -frounding-math -fno-stack-protector -Wstrict-prototypes -Wold-style-definition -fmath-errno -DHAVE_EPOLL -DHAVE_INOTIFY -DHAVE_NETLINK *-fpie* -I../include -I/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/nscd  -I/home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi  -I../sysdeps/unix/sysv/linux/arm  -I../sysdeps/arm/nptl  -I../sysdeps/unix/sysv/linux/include -I../sysdeps/unix/sysv/linux  -I../sysdeps/nptl  -I../sysdeps/pthread  -I../sysdeps/gnu  -I../sysdeps/unix/inet  -I../sysdeps/unix/sysv  -I../sysdeps/unix/arm  -I../sysdeps/unix  -I../sysdeps/posix  -I../sysdeps/arm/armv7/multiarch  -I../sysdeps/arm/armv7  -I../sysdeps/arm/armv6t2  -I../sysdeps/arm/armv6  -I../sysdeps/arm/include -I../sysdeps/arm  -I../sysdeps/wordsize-32  -I../sysdeps/ieee754/flt-32  -I../sysdeps/ieee754/dbl-64  -I../sysdeps/ieee754  -I../sysdeps/generic  -I.. -I../libio -I. -nostdinc -isystem /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/recipe-sysroot-native/usr/bin/arm-poky-linux-gnueabi/../../lib/arm-poky-linux-gnueabi/gcc/arm-poky-linux-gnueabi/8.3.0/include -isystem /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/recipe-sysroot-native/usr/bin/arm-poky-linux-gnueabi/../../lib/arm-poky-linux-gnueabi/gcc/arm-poky-linux-gnueabi/8.3.0/include-fixed -isystem /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/recipe-sysroot/usr/include  -D_LIBC_REENTRANT -include /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/libc-modules.h -DMODULE_NAME=nscd -include ../include/libc-symbols.h  -DPIC -D_FORTIFY_SOURCE=2    -DTOP_NAMESPACE=glibc -o /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/nscd/res_hconf.o -MD -MP -MF /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/nscd/res_hconf.o.dt -MT /home/varga-r/projects/yocto-tq-mba6x/build/tmp/work/cortexa9t2hf-neon-poky-linux-gnueabi/glibc/2.29-r0/build-arm-poky-linux-gnueabi/nscd/res_hconf.o
...
</snip>

I am not sure, if this is relevant... just in case.

Thanks for your support.

--
Rob