Description of problem:

%gobuild macro on c9s seems to have dropped `BUILDTAGS` from its definition which is causing many build failures for podman / buildah etc.

See: https://copr.fedorainfracloud.org/coprs/rhcontainerbot/podman-next/build/6220412/ . The c9s builds on that copr used to pass until recently.

Also, see the %gobuild defs on Fedora v/s C9S

On C9S

1. rpm --eval %gobuild

CGO_CPPFLAGS="D_FORTIFY_SOURCE=2 -fstack-protector-all" go build -compiler gc -buildmode pie '-tags=rpm_crashtraceback libtrust_openssl ' -ldflags "-linkmode=external -compressdwarf=false ${LDFLAGS:} B 0x$(head -c20 /dev/urandom|od -An -tx1|tr -d ' \n') -extldflags '-Wl,-z,relro -Wl,-as-needed -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 '" -a -v -x ;

On Fedora:
$ rpm --eval %gobuild

1. https://pagure.io/go-rpm-macros/pull-request/38
2. Most of the default LDFLAGS for Fedora are not supported so we don't want
3. LDFLAGS to be automatically initialized with the Fedora flags.

1. https://bugzilla.redhat.com/show_bug.cgi?id=995136#c12
   GO111MODULE=off \
   go build buildmode pie -compiler gc -tags="rpm_crashtraceback ${BUILDTAGS:}" ldflags "${LDFLAGS:} B 0x$(head -c20 /dev/urandom|od -An -tx1|tr -d ' \n') -compressdwarf=false -linkmode=external -extldflags '-Wl,-z,relro -Wl,as-needed -Wl,-z,now -specs=/usr/lib/rpm/redhat/redhat-hardened-ld -specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 -Wl,-build-id=sha1 '" -a -v -x ;