Ok I work on the application side and am not that familiar with COPR infrastructure.

So can you point me directly to the files that contain the actual failure messages beyond COPR failed

Sure, builds available here:

https://copr.fedorainfracloud.org/coprs/odubaj/autoconf-2.70/package/pveclib/

Click on appropriate buid_id -> builder-live.log.gz 
l
Please check your fix using pull-requests with the prepared copr or locally with mock> more info here: https://fedoraproject.org/wiki/Changes/Autoconf_271#How_To_Test

Also do not hesitate to share you possible fix in the linked document in change proposal.

Looked at: https://copr-be.cloud.fedoraproject.org/results/odubaj/autoconf-2.70/fedora-rawhide-x86_64/02013224-pveclib/builder-live.log.gz

and found.

Complete!
Finish: build setup for pveclib-1.0.4-5.fc35.src.rpm
Start: rpmbuild pveclib-1.0.4-5.fc35.src.rpm
error: Architecture is not included: x86_64
Building target platforms: x86_64
Building for target x86_64
Finish: rpmbuild pveclib-1.0.4-5.fc35.src.rpm
Finish: build phase for pveclib-1.0.4-5.fc35.src.rpm
INFO: chroot_scan: 3 files copied to /var/lib/copr-rpmbuild/results/chroot_scan
INFO: /var/lib/mock/fedora-rawhide-x86_64-1614043643.833508/root/var/log/dnf.rpm.log
/var/lib/mock/fedora-rawhide-x86_64-1614043643.833508/root/var/log/dnf.librepo.log
/var/lib/mock/fedora-rawhide-x86_64-1614043643.833508/root/var/log/dnf.log
ERROR: Exception(/var/lib/copr-rpmbuild/results/pveclib-1.0.4-5.fc35.src.rpm) Config(fedora-rawhide-x86_64) 0 minutes 22 seconds
INFO: Results and/or logs in: /var/lib/copr-rpmbuild/results
INFO: Cleaning up build root ('cleanup_on_failure=True')
Start: clean chroot
INFO: unmounting tmpfs.
Finish: clean chroot
INFO: unmounting tmpfs.
ERROR: Command failed: 
 # /usr/bin/systemd-nspawn -q -M 68748cde7166484b9672f34ca7e9df01 -D /var/lib/mock/fedora-rawhide-x86_64-1614043643.833508/root -a -u mockbuild --capability=cap_ipc_lock --rlimit=RLIMIT_NOFILE=10240 --capability=cap_ipc_lock --bind=/tmp/mock-resolv.p0mjvpai:/etc/resolv.conf --bind=/dev/btrfs-control --bind=/dev/loop-control --bind=/dev/loop0 --bind=/dev/loop1 --bind=/dev/loop2 --bind=/dev/loop3 --bind=/dev/loop4 --bind=/dev/loop5 --bind=/dev/loop6 --bind=/dev/loop7 --bind=/dev/loop8 --bind=/dev/loop9 --bind=/dev/loop10 --bind=/dev/loop11 --console=pipe --setenv=TERM=vt100 --setenv=SHELL=/bin/bash --setenv=HOME=/builddir --setenv=HOSTNAME=mock --setenv=PATH=/usr/bin:/bin:/usr/sbin:/sbin --setenv=PROMPT_COMMAND=printf "\033]0;<mock-chroot>\007" --setenv=PS1=<mock-chroot> \s-\v\$  --setenv=LANG=C.UTF-8 --resolv-conf=off bash --login -c /usr/bin/rpmbuild -bb --target x86_64 --nodeps /builddir/build/SPECS/pveclib.spec

Copr build error: Build failed

I would expect pveclib to fail on x86_64 build because it is a ppc64/ppc64le only package.

pveclib.spec:
ExclusiveArch: ppc %{power64}

Does COPR (currently) support ppc64le targets? Is there way to direct these autoconf builds to ppc64le systems?

Currently not. Maybe testing it locally by installing autoconf-2.71 directly on the system could be an option ?

Gentle ping.

Ok installed autoconf-2.71 on a local POWER8 VM running Fedora 33.

Ran autoreconf on my current release candidate just for fun.

It complained about AC_PROG_LIBTOOL and suggested I run autoupdate.

Did that and then autoreconf and automake. Then configure, make, make check.

So far so good. I will also test the v1.0.4 tag which is current in Fedora. and rpmbuild

Thanks for your effort!

We already provide a possibility to test packages also on non-86_64 architectures, please see https://fedoraproject.org/wiki/Changes/Autoconf_271#How_To_Test

Do I need:
Go to the releng/fedora-scm-requests API tokens page

Which implies I need: Ask @pingou or other admin to [create](https://pagure.io/fedora-infra/howtos/blob/main/f/create_fedscm_admin_token.md) a src.fp.o scm admin token for you

Any way I am not set up for this. Likely I let tokens lapse as copr simply was not available for ppc64le.

I will need some clues to the start of this tail.

I am afraid I cannot help you with the token.

This bug appears to have been reported against 'rawhide' during the Fedora 35 development cycle.
Changing version to 35.

Autoconf-2.71 Fedora Change is completed. According to this, I am closing this tracker and if any FTBFS will appear in Fedora Rawhide, new F36FTBFS tracker will be created for this purposes, thank you for cooperation.