t -> gcc
BUILDSTDERR: executing ./autoconf/alignment -> 3
BUILDSTDERR: executing ./autoconf/ascpp -> gcc -c -x assembler-with-cpp
BUILDSTDERR: executing ./autoconf/arflags -> qc
BUILDSTDERR: executing ./autoconf/ranlib -> yes
BUILDSTDERR: executing ./autoconf/strip -> true
BUILDSTDERR: executing ./autoconf/thread -> -DGC_LINUX_THREADS -D_REENTRANT -DGC_THREADS -DNO_HANDLE_FORK -DTHREAD_LOCAL_ALLOC -DFINALIZE_ON_DEMAND -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -fasynchronous-unwind-tables -fstack-clash-protection -fwrapv -D_FILE_OFFSET_BITS=64 -Wno-unused
BUILDSTDERR: executing ./autoconf/pthread -> -lpthread
BUILDSTDERR: executing ./autoconf/pthreadlock -> 1
BUILDSTDERR: executing ./autoconf/pthreadspinlock -> 1
BUILDSTDERR: executing ./autoconf/pthreadmutexrec -> 1
BUILDSTDERR: executing ./autoconf/pthreadcondvtimedwait -> 1
BUILDSTDERR: executing ./autoconf/pthreadtimedjoin -> 1
BUILDSTDERR: executing ./autoconf/pthreadlocalstorage -> __thread
BUILDSTDERR: executing ./autoconf/pthreadkill -> TGKILL
BUILDSTDERR: executing ./autoconf/nbprocs -> 4
BUILDSTDERR: executing ./autoconf/semaphore -> 1
BUILDSTDERR: executing ./autoconf/lockf -> 1
BUILDSTDERR: executing ./autoconf/gcflags -> -DNO_DEBUGGING -Iinclude -Ilibatomic_ops-install/include -DATOMIC_UNCOLLECTABLE -DNO_EXECUTE_PERMISSION
BUILDSTDERR: executing ./autoconf/maemo.arm -> no
+ Installing custom GC (gc-8.0.2) source code.
BUILDSTDERR: executing ./autoconf/gcconfigureopt -> 
+ Configuring custom GC (gc-8.0.2)...
BUILDSTDERR: ./config.guess: unable to guess system type
BUILDSTDERR: This script, last modified 2014-11-04, has failed to recognize
BUILDSTDERR: the operating system you are using. It is advised that you
BUILDSTDERR: download the most up to date version of the config scripts from
BUILDSTDERR:   http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD
BUILDSTDERR: and
BUILDSTDERR:   http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=HEAD
BUILDSTDERR: If the version you run (./config.guess) is already up to date, please
BUILDSTDERR: send the following data and any information you think might be
BUILDSTDERR: pertinent to <config-patches@gnu.org> in order to provide the needed
BUILDSTDERR: information to handle your system.
BUILDSTDERR: config.guess timestamp = 2014-11-04
BUILDSTDERR: uname -m = riscv64
BUILDSTDERR: uname -r = 5.2.0-0.rc7.git0.1.0.riscv64.fc31.riscv64
BUILDSTDERR: uname -s = Linux
BUILDSTDERR: uname -v = #1 SMP Tue Jul 2 12:47:15 UTC 2019
BUILDSTDERR: /usr/bin/uname -p = riscv64
BUILDSTDERR: /bin/uname -X     = 
BUILDSTDERR: hostinfo               = 
BUILDSTDERR: /bin/universe          = 
BUILDSTDERR: /usr/bin/arch -k       = 
BUILDSTDERR: /bin/arch              = riscv64
BUILDSTDERR: /usr/bin/oslevel       = 
BUILDSTDERR: /usr/convex/getsysinfo = 
BUILDSTDERR: UNAME_MACHINE = riscv64
BUILDSTDERR: UNAME_RELEASE = 5.2.0-0.rc7.git0.1.0.riscv64.fc31.riscv64
BUILDSTDERR: UNAME_SYSTEM  = Linux
BUILDSTDERR: UNAME_VERSION = #1 SMP Tue Jul 2 12:47:15 UTC 2019
BUILDSTDERR: configure: error: cannot guess build type; you must specify one
configure gc fail, see configure.log file.
error: 
RPM build errors:
BUILDSTDERR: Bad exit status from /var/tmp/rpm-tmp.KDFlwh (%build)
BUILDSTDERR:     Bad exit status from /var/tmp/rpm-tmp.KDFlwh (%build)
Child return code was: 1
EXCEPTION: [Error()]
Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/mockbuild/trace_decorator.py", line 96, in trace
    result = func(*args, **kw)
  File "/usr/lib/python3.7/site-packages/mockbuild/util.py", line 700, in do
    raise exception.Error("Command failed: \n # %s\n%s" % (command, output), child.returncode)
mockbuild.exception.Error: Command failed: 
 # bash --login -c /usr/bin/rpmbuild -bb --target riscv64 --nodeps /builddir/build/SPECS/bigloo.spec