我在Mac中运行flutter doctor：出现以下问题：
$ flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, v1.12.13+hotfix.5, on Mac OS X 10.14 18A391, locale
zh-Hans-CN)
[✗] Android toolchain - develop for Android devices
✗ Unable to locate Android SDK.
Install Android Studio from:
https://developer.android.com/studio/index.html
On first launch it will assist you in installing the Android SDK
components.
(or visit https://flutter.dev/setup/#android-setup for detailed
instructions).
If the Android SDK has been installed to a custom location, set
ANDROID_HOME to that location.
You may also want to add it to your PATH environment variable.
但是我已经在Mac上通过此路径/Users/delo/software/android-sdk-macosx安装了Android SDK。
在问这个问题之前，我已经按照this post将/Users/delo/software/android-sdk-macosx添加到我的/etc/paths.d/android-sdk文件中，并且this post添加了path-to-android-sdk/tools和path-to-android-sdk/platform-tools。
但仍然存在此问题。
EDIT-01
这是echo $PATH：
/Library/Frameworks/Python.framework/Versions/3.5/bin:/Users/delo/.rvm/gems/ruby-2.3.3/bin:/Users/delo/.rvm/gems/ruby-2.3.3@global/bin:/Users/delo/.rvm/rubies/ruby-2.3.3/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Applications/VMware Fusion.app/Contents/Public:/Users/delo/software/android-sdk-macosx:/usr/local/share/dotnet:/opt/X11/bin:~/.dotnet/tools:/Library/Frameworks/Mono.framework/Versions/Current/Commands:/Applications/Wireshark.app/Contents/MacOS:/opt/local/bin:/usr/local/mysql/bin:/usr/local/Cellar/go/1.7.6/bin:/Users/delo/.rvm/bin:/usr/local/sbin:/Users/delo/software/android-sdk-macosx/tools:/Users/delo/software/android-sdk-macosx/platform-tools
[我看到您的$ PATH已经添加了ANDROID SDK PATH及其tools和platform-tools PATH，但是没有配置flutter PATH，但是您仍然可以运行flutter doctor命令，应该有复制错误。
根据您的情况，必须有ANDROID_HOME变量配置错误，
您应该遵循正确的方法：
附加
export PATH=/path/to/your/flutter/bin:$PATH
export ANDROID_HOME="/path/to/your/android-sdk"
export PATH=${PATH}:${ANDROID_HOME}/tools
export PATH=${PATH}:${ANDROID_HOME}/platform-tools
到
然后您只是source ~/.bash_profile。