for i in fftw-${PKGVER/+/-}-{single,double,long-double,std}; do
    abinfo "Preparing source tree for $i ..."
    cp -av "$SRCDIR"/fftw-${PKGVER/+/-} "$SRCDIR"/$i
done

for i in $(find "$SRCDIR" -name config.guess -o -name config.sub); do \
    abinfo "Copying replacement $i ..."
    # FIXME: hard-coded automake version.
    # Adapted from redhat-rpm-config.
    # https://src.fedoraproject.org/rpms/redhat-rpm-config/blob/rawhide/f/macros#_192
        cp -v "/usr/bin/$(basename "$i")" "$i" \
            || abdie "Failed to copy replacement $i: $?."; \
done
