`flutter doctor` report error `Android toolchain - develop for Android devices` - flutter

Question

I run flutter doctor in my Mac:
there comes an issue below:
$ 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.
But I have installed Android SDK in my Mac this path /Users/delo/software/android-sdk-macosx.
before ask this question I have follow this post to add the /Users/delo/software/android-sdk-macosx in my /etc/paths.d/android-sdk file, and this post add path-to-android-sdk/tools and path-to-android-sdk/platform-tools.
but there is still have this issue.
EDIT-01
This is the 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

Answer 1

I see your $PATH have add the ANDROID SDK PATH and its tools and platform-tools PATH, but did not config the flutter PATH, but you can still run flutter doctor command, there should be copy error.
in your case, there must be ANDROID_HOME variable config error,
you should follow the correct way :
append the
export PATH=/path/to/your/flutter/bin:$PATH
export ANDROID_HOME="/path/to/your/android-sdk"
export PATH=${PATH}:${ANDROID_HOME}/tools
export PATH=${PATH}:${ANDROID_HOME}/platform-tools
to
then you just source ~/.bash_profile.

Answer 2

I believe the problem is in the PATH of Android SDK Command-Line Tools and Android SDK Build Tools.
Put the lines at the end of the .bachrc file:
export ANDROID_HOME="/home/XXX/Android/Sdk/"
export PATH="$PATH:${ANDROID_HOME}cmdline-tools/latest/bin/:${ANDROID_HOME}build-tools/33.0.0/:${ANDROID_HOME}platform-tools/"
Note that latest and 33.0.0 must be changed according to your installation.