update dnf cache on centos (facebookincubator#302)

Signed-off-by: Yuan Zhou <[email protected]>

scripts/setup-centos7.sh

@@ -231,6 +231,8 @@ function install_velox_deps {
   run_and_time install_conda
 }
 
+$SUDO dnf makecache
+
 # dnf install dependency libraries
 dnf_install epel-release dnf-plugins-core # For ccache, ninja
 # PowerTools only works on CentOS8
@@ -252,6 +254,8 @@ dnf_install gettext-devel texinfo help2man
 # Activate gcc9; enable errors on unset variables afterwards.
 # GCC9 install via yum and devtoolset
 # dnf install gcc-toolset-9 only works on CentOS8
+
+$SUDO yum makecache
 yum_install centos-release-scl
 yum_install devtoolset-9
 source /opt/rh/devtoolset-9/enable || exit 1

scripts/setup-centos8.sh

@@ -32,6 +32,8 @@ function dnf_install {
   $SUDO dnf install -y -q --setopt=install_weak_deps=False "$@"
 }
 
+$SUDO dnf makecache
+
 dnf_install epel-release dnf-plugins-core # For ccache, ninja
 $SUDO dnf config-manager --set-enabled powertools
 dnf_install ninja-build ccache gcc-toolset-9 git wget which libevent-devel \