mac下，安装了brew，但是使用brew安装sysstat时报错：
zhangyanyandeMacBook-Pro:~ zhangyanyan$ brew install sysstat
Error: No available formula with the name “sysstat”
==> Searching for a previously deleted formula (in the last month)…
Warning: homebrew/core is shallow clone. To get complete history run:
git -C “$(brew --repo homebrew/core)” fetch --unshallow

Error: No previously deleted formula found.
==> Searching for similarly named formulae…
Error: No similarly named formulae found.
==> Searching taps…
==> Searching taps on GitHub…
Error: No formulae found in taps.