Exclude .cxx folders from git as part of the flutter create templates.

** /.cxx
https://stackoverflow.com/questions/66129837/about-the-gitignore-question-cxx-folder-in-the-android-project

I believe that an unintended side effect of #160260 is that we are seeing more native bin directories when working with apps.

This bug tracks updating the templates. As an aside the blog post for the next release might want to warn about this and we want to update our own repos to exclude this folder.

Ignore cxx folders for all of flutter/flutter (#160381)

Do you know what circumstances cause these cxx directories to appear? I tried building the examples/flutter_view app, as well as a new sample app from templates, and didn't see them.

They showed up while I was working on a different pr that was opened in android studio. Specifically dev/integration_test/display_cutout_rotation

Also I didnt check if the cxx directories stopped showing up without your pr. It was only a guess on my part.

Do you know what circumstances cause these cxx directories to appear? I tried building the examples/flutter_view app, as well as a new sample app from templates, and didn't see them.

This directory is created only when I run the app in profile or release mode on a real device. It doesn't show up when building the app with flutter build

For us with the Zulip app at https://github.com/zulip/zulip-flutter, flutter build apk is enough to make an android/app/.cxx/ directory appear. So is flutter build apk --debug, and so is flutter run targeting an Android device.

The previous Flutter commit we were using was 1c1f357 from Dec 8, and with that version we didn't have this symptom. (Now we're using 65ff060 which is from Dec 23, later than the reports above.)

Because the directory has a ton of files in it, having it present without being in .gitignore produces an alarming amount of "new files" output for our contributors using VS Code. So I agree it should probably get mentioned in the blog post and release notes — people are definitely going to notice, and it's best if they feel they were forewarned.

Also I think the hash_key.txt file inside the generated directory confirms this is indeed due to the logic added in #160260 / 2948917 :

$ cat android/app/.cxx/Debug/416t271r/hash_key.txt; echo
…
-H/home/greg/n/flutter/flutter/packages/flutter_tools/gradle/src/main/groovy
…
-Wno-dev
--no-warn-unused-cli

That directory is where that commit's stub CMakeLists.txt goes. And those two flags at the end are a match for those added in that code:

                externalNativeBuild {
                    cmake {
                        // CMake will print warnings when you try to build an empty project.
                        // These arguments silence the warnings - our project is intentionally
                        // empty.
                        arguments("-Wno-dev", "--no-warn-unused-cli")
                    }

gitignore: Ignore CMake directory generated on Android build

Looks like these are also gitignored in a new (pure) Android project created from Android Studio, example
https://github.com/gmackall/help_w_a2a/blob/main/host_app/.gitignore#L14.

Adding to the templates sounds correct to me, and I'll draft a section for the blog post.

[Android] Add `.cxx` directories to app template `.gitignore` (#161069)

Update integration test and benchmark Android .gitignore files to mat…

I am suddenly getting configure_fingerprint.bin files from android/app/.cxx/RelWithDebInfo added to my repository. Not sure which change caused this unfortunately, but I recently did the following:

Upgraded to Flutter 3.29
Upgraded Kotlin to 2.1.10
Upgraded Gradle plugin to 8.8.0
gradle-wrapper.properties to gradle-8.10.2-all.zip

Ignoring .cxx folders

Ignore .cxx directory

Android用の.gitignoreファイルに「**/.cxx/」を追加しました。

I read a lot of github issues related to this. Everyone stated the obvious of adding to .gitignore. I have done that.

I did not find a discussion about build artifacts in our source code folders. So if I run 'flutter clean', this build artifact remains. Only method to is to remove it manually. This is bad design and hopefully someone will figure out how to move it to the build directory

android/app/.cxx should not exist, it is a build tools failure

I read a lot of github issues related to this. Everyone stated the obvious of adding to .gitignore. I have done that.

I did not find a discussion about build artifacts in our source code folders. So if I run 'flutter clean', this build artifact remains. Only method to is to remove it manually. This is bad design and hopefully someone will figure out how to move it to the build directory

android/app/.cxx should not exist, it is a build tools failure

This is a good point. I think we can configure this with https://developer.android.com/reference/tools/gradle-api/8.3/null/com/android/build/api/dsl/Cmake#buildStagingDirectory(kotlin.Any)

I read a lot of github issues related to this. Everyone stated the obvious of adding to .gitignore. I have done that.
I did not find a discussion about build artifacts in our source code folders. So if I run 'flutter clean', this build artifact remains. Only method to is to remove it manually. This is bad design and hopefully someone will figure out how to move it to the build directory
android/app/.cxx should not exist, it is a build tools failure

This is a good point. I think we can configure this with https://developer.android.com/reference/tools/gradle-api/8.3/null/com/android/build/api/dsl/Cmake#buildStagingDirectory(kotlin.Any)

Interestingly it looks like the AGP maintainers sort of disagree, and explicitly say not to to put the external native build output directory in your projects temporary build directory. I think it probably isn't a problem for us, though, as we aren't actually building anything anyways (we are just tricking AGP into downloading the NDK).

Put up #166277 to move the build staging directory to within the build/ directory.

Move `.cxx` directory out of `android/app` (#166277)

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.

Move `.cxx` directory out of `android/app` (flutter#166277)

Navigation Menu

Repository navigation

Exclude .cxx folders from git as part of the flutter create templates. #160372

5 remaining items

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Exclude .cxx folders from git as part of the flutter create templates. #160372

Description

Activity

gmackall commented on Dec 17, 2024

reidbaker commented on Dec 17, 2024

reidbaker commented on Dec 17, 2024

khoadng commented on Dec 19, 2024

gnprice commented on Dec 27, 2024

gnprice commented on Dec 27, 2024

gmackall commented on Jan 2, 2025

5 remaining items

corepuncher commented on Feb 22, 2025

gasaichandesu commented on Mar 28, 2025

j3g commented on Mar 29, 2025

gmackall commented on Mar 30, 2025

gmackall commented on Mar 31, 2025

github-actions commented on Apr 15, 2025

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions