$ brew upgrade
...........................................
==> Upgrading 5 outdated packages:
tomcat 9.0.39 -> 9.0.40
gradle 6.7 -> 6.7.1
opencv 4.5.0_3 -> 4.5.0_4
vtk 9.0.1_1 -> 9.0.1_2
imagemagick 7.0.10-38 -> 7.0.10-39
==> Upgrading tomcat 9.0.39 -> 9.0.40
==> Downloading https://www.apache.org/dyn/closer.lua?path=tomcat/tomcat-9/v9.0.
==> Downloading from https://mirror.bit.edu.cn/apache/tomcat/tomcat-9/v9.0.40/bi
######################################################################## 100.0%
Error: Your CLT does not support macOS 11.0.
It is either outdated or was modified.
Please update your CLT or delete it if no updates are available.
Error: An exception occurred within a child process:
SystemExit: exit