While working on reproducible builds for openSUSE, I found that
since the introduction of -flto=%jobs
several packages started to vary between builds
because they embed the CFLAGS somewhere in the rpm:
fldigi gmp haproxy ImageMagick lyx neovim tboot tcl

Not all packages have been tested yet.

Steps to Reproduce:
osc co openSUSE:Factory/fldigi && cd $_
for i in 1 2 ; do
  osc build --vm-type=kvm -j$i --disable-debuginfo --keep-pkg=.rpm$i
done
/usr/lib/build/pkg-diff.sh .rpm{1,2}/fldigi-*-0.x86_64.rpm