A problem occurred evaluating project ':app'. > path may not be null or empty string. path='null'

Question

Iam facing error while iam trying to run flutter.

 D:\fluttapp\testbuild>flutter run
Launching lib/main.dart on Google Pixel 2 XL in debug mode...
Initializing gradle...                                       2.1s
Resolving dependencies...
* Error running Gradle:
ProcessException: Process "D:\fluttapp\testbuild\android\gradlew.bat" exited abnormally:

FAILURE: Build failed with an exception.

* Where:
Build file 'D:\fluttapp\testbuild\android\app\build.gradle' line: 57

* What went wrong:
A problem occurred evaluating project ':app'.
> path may not be null or empty string. path='null'

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to
get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 6s
  Command: D:\fluttapp\testbuild\android\gradlew.bat app:properties


Please review your Gradle project setup in the android/ folder.

D:\fluttapp\testbuild>flutter doctor -v
[√] Flutter (Channel beta, v1.1.8, on Microsoft Windows [Version 10.0.17134.556], locale
    en-IN)
    • Flutter version 1.1.8 at D:\flutter
    • Framework revision 985ccb6d14 (3 weeks ago), 2019-01-08 13:45:55 -0800
    • Engine revision 7112b72cc2
    • Dart version 2.1.1 (build 2.1.1-dev.0.1 ec86471ccc)

[√] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
    • Android SDK at D:\Users\Bhanu\AppData\Local
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-28, build-tools 28.0.3
    • ANDROID_HOME = D:\Users\Bhanu\AppData\Local
    • Java binary at: D:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)
    • All Android licenses accepted.

[√] Android Studio (version 3.1)
    • Android Studio at D:\Program Files\Android\Android Studio
    • Flutter plugin version 29.0.1
    • Dart plugin version 173.4700
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)

[√] Connected device (1 available)
    • Google Pixel 2 XL • 192.168.50.101:5555 • android-x86 • Android 9 (API 28)

• No issues found!

I have add repo here. I have taken sample code to make release app version but unable to generate them. Key store is created and add to code repo

https://github.com/bhanu888/buildapk

Toilet

For anyone looking into this github.com/flutter/flutter/issues/27306 has a few additional information (like gradle file with signingConfigs) – Gravestone

having same issue! when i want to release the apk – Salol

had this issue. Flutter clean did the job – Whitehot

Answer 1

For me it was a pathing problem.

I was following the flutter guide https://flutter.io/docs/deployment/android

Create a file named <app dir>/android/key.properties that contains a reference to your keystore:

For some reason I (wrongfully) placed my "key.properties" in the app_dir/android/app folder, and this gave me the error.

* What went wrong:
A problem occurred evaluating project ':app'.
> path may not be null or empty string. path='null'

So check your pathing, and where your files are located :)

Bonus info: What helped med was checking the "gradle.build" file with different settings, and it was always the storeFile file(keystoreProperties['storeFile']) that gave me problems. Try commenting it out, or change it to:

storeFile file("key.jks")  

If this works, you know that you have the correct path to your "key.jks" file. Then try introducing the poperties file (keystoreProperties) Like

storeFile file(keystoreProperties['storeFile']) 

This did not work at first, but it does now :)

So check again that you "key.jks" and "key.properties" files are located the "correct" places, and how you point to them.

Lezlie

Does this actually solve the question? It sounds like you are just describing an issue you had and how you solved it. – Revel

I hope so, but I cannot know, we can only know when op returns. . it solved my issue which looks like the same issue as the OP. The error screens described by the op and the process was the same that I went though. and the fix was providing the correct paths :) – Lezlie

I did your fix, and still have this problem. null and null everywhere. Tell me, what is correct path? ex /Users/smth/key.jks but should i quote it? Is it unix syntax of path, or windows? – Mistassini

My keystore.jks file is located in "FlutterApp/android/app/keystore.jks". which is next to "FlutterApp/android/app/build.gradle". Be aware that there are two build.gradle files in a flutter project. – Lezlie

Answer 2

If you downloaded the app from github, it is possible that signing configs are note adapted. Try like this to comment code on android/app/build.gradle :

    /*signingConfigs {
    release {
  keyAlias keystoreProperties['keyAlias']
        keyPassword keystoreProperties['keyPassword']
        storeFile file(keystoreProperties['storeFile'])
        storePassword keystoreProperties['storePassword']
    }
}
buildTypes {
    release {
        // TODO: Add your own signing config for the release build.
        // Signing with the debug keys for now, so `flutter run --release` works.
        signingConfig signingConfigs.release
    }
   */`

Solution find on : https://github.com/transistorsoft/flutter_background_geolocation/issues/18

Deadlock

Answer 3

The problem occurred when you download an app from github  

go to > android > app > build.gradle

in your build gradle file :--
signingConfigs {
release {
    keyAlias keystoreProperties['keyAlias']
    keyPassword keystoreProperties['keyPassword']
    storeFile file(keystoreProperties['storeFile'])
    storePassword keystoreProperties['storePassword']
}

}

Replace:      storeFile file(keystoreProperties['storeFile'])
to:  storeFile file("key.jks")

Aurthur

Answer 4

I have used the

storeFile file(keystoreProperties['storeFile'])

on compiling it had thrown an error. But after replacing the above line with

storeFile file("key.jks")

Build was successful. I don't know how that has happened, though.

Shooin

If you want to know something then you post a question, if you want to show how to resolve a problem you post an answer. Do you want to present this as a solution (remove the phrase with the question mark) or do you want an answer (then ask a new question)? – Redpoll

The solution they have stated had resulted in the build error once after changing the code line to ' storeFile file("key.jks")' the build succeeded. And I just want to give the answer that both solutions imply irrespective to their working methodology – Shooin

I want to know where to paste key file so that it can run – Bojorquez

Answer 5

If you are just testing or debugging and not releasing, you might consider changing the build type to be debug instead of release.

In <APP_FOLDER>/android/app/build.gradle

buildTypes {
        release {
            signingConfig signingConfigs.debug
       }
    }

Heliport

Answer 6

1)Check the Key in this Project"key.jks"

Go to "gradle.build"

and replace it

storeFile file("key.jks")  

with

storeFile file(keystoreProperties['storeFile']) 

Giuseppe

Answer 7

There must be 2 files one with suffix

1. "debug"
2. "release" Add these two file in your project through file explorer Then edit the path in your file known as local.properties
3. debugStoreFile=C:/Users/Sachin/Android_Studio_project...
4. storeFile=C:/Users/Sachin/Android_Studio_project...

Teeters

Answer 8

it works for me after deleting or comments

these lines(related to App key signing) from "build.gradle" file

//android.signingConfigs.release.storeFile rootProject.file(props.keyStore)
//android.signingConfigs.release.storePassword props.keyStorePassword
//android.signingConfigs.release.keyAlias props.keyAlias
//android.signingConfigs.release.keyPassword props.keyAliasPassword

Smoothbore

Answer 9

this worked for me

Replace: storeFile file(keystoreProperties['storeFile'])

to: storeFile file("key.jks")

Raber

Answer 10

Though the popular ans will do, second approach-> u need to add null check to storefile in path(android/app/build.gradle)

    signingConfigs{
      release {
        keyAlias keystoreProperties['keyAlias']
        keyPassword keystoreProperties['keyPassword']
        // storeFile file(keystoreProperties['storeFile'])
        storeFile keystoreProperties['storeFile'] file(keystoreProperties['storeFile']) : null
        storePassword keystoreProperties['storePassword']
    }
}

Piling