>>> fio 3.27 Extracting
gzip -d -c /home/buildroot/autobuild/instance-3/dl/fio/fio-3.27.tar.gz | tar --strip-components=1 -C /home/buildroot/autobuild/instance-3/output-1/build/fio-3.27   -xf -
>>> fio 3.27 Patching
>>> fio 3.27 Configuring
(cd /home/buildroot/autobuild/instance-3/output-1/build/fio-3.27; PATH="/home/buildroot/autobuild/instance-3/output-1/host/bin:/home/buildroot/autobuild/instance-3/output-1/host/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin" ./configure --cc="/home/buildroot/autobuild/instance-3/output-1/host/bin/arm-none-linux-gnueabi-gcc" --extra-cflags="-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -Os -g0 -D_FORTIFY_SOURCE=1")
Operating system              Linux
CPU                           arm
Big endian                    no
Compiler                      /home/buildroot/autobuild/instance-3/output-1/host/bin/arm-none-linux-gnueabi-gcc
Cross compile                 yes

Static build                  no

Your compiler doesn't support C11 atomics. gcc 4.9/clang 3.6 are the
minimum versions with it - perhaps your compiler is too old?
C11 atomics support not found
Configure failed, check config.log and/or the above output
package/pkg-generic.mk:249: recipe for target '/home/buildroot/autobuild/instance-3/output-1/build/fio-3.27/.stamp_configured' failed
make: *** [/home/buildroot/autobuild/instance-3/output-1/build/fio-3.27/.stamp_configured] Error 1
make: Leaving directory '/home/buildroot/autobuild/instance-3/buildroot'