今天用 brew install cmake。
==> Downloading https://homebrew.bintray.com/bottles/cmake-3.9.6.sierra.bottle.tar.gz
######################################################################## 100.0%
==> Pouring cmake-3.9.6.sierra.bottle.tar.gz
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
Could not symlink share/aclocal/cmake.m4
/usr/local/share/aclocal is not writable.
You can try again using:
brew link cmake
==> Caveats
Emacs Lisp files have been installed to:
/usr/local/share/emacs/site-lisp/cmake
==> Summary
?? /usr/local/Cellar/cmake/3.9.6: 2,267 files, 31.7MB
brew install cmake
Warning: cmake 3.9.6 is already installed, it‘s just not linked.
You can use `brew link cmake` to link this version.
x-MacBook-Pro:primecount-master zilong$ brew link cmake
Linking /usr/local/Cellar/cmake/3.9.6...
Error: Could not symlink share/aclocal/cmake.m4
/usr/local/share/aclocal is not writable.
x-MacBook-Pro:primecount-master zilong$ brew link cmake
Linking /usr/local/Cellar/cmake/3.9.6...
Error: Could not symlink share/aclocal/cmake.m4
/usr/local/share/aclocal is not writable.
哦，原来是权限问题，那么通过赋权即可
sudo chown -R `whoami`:admin /usr/local/share/aclocal
再敲一遍即可
brew link cmake
原文：http://www.cnblogs.com/hero4china/p/brew-install-cmake.html