我正在用brew在os mojave上安装mysql。我有个错误：

Stack:
  0   __exceptionPreprocess (in CoreFoundation)
  1   objc_exception_throw (in libobjc.A.dylib)
  2   -[DVTExtension valueForKey:error:] (in DVTFoundation)
  3   _IDEInitializeOnePlugInAndPrerequisites (in IDEFoundation)
  4   _IDEInitializePlugIns (in IDEFoundation)
  5   IDEInitialize (in IDEFoundation)
  6   -[Xcode3CommandLineBuildTool run] (in Xcode3Core)
  7  0x0000000103785202 (in xcodebuild)
  8   start (in libdyld.dylib)

sh: line 1: 10700 Abort trap: 6           
/Applications/Xcode.app/Contents/Developer/usr/bin/xcodebuild -sdk macosx -find git 2> /dev/null
git: error: unable to find utility "git", not a developer tool or in PATH
Error: Failure while executing; `git config --local --replace-all homebrew.private true` exited with 72.

有人知道为什么会这样吗？