Xcode 26 beta stricter codesign validation rejecting Flutter.framework

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While testing Flutter applications on macOS 26 beta with Xcode 26 beta, iOS builds consistently fail during Flutter.framework codesigning with:

"resource fork, Finder information, or similar detritus not allowed"

Investigation suggests newer Xcode beta versions now reject additional extended attributes beyond com.apple.FinderInfo during codesigning.

Flutter tooling currently removes only:

xattr -r -d com.apple.FinderInfo

Replacing it with:

xattr -cr

successfully resolves the issue.

Environment:

macOS 26.4.1 beta
Xcode 26.4.1 beta
Apple Silicon (ARM64)
Flutter 3.41.9

Flutter issue: https://github.com/flutter/flutter/issues/186372

Apple Feedback Assistant report: FB22756923

Interested to know whether other developers on Xcode 26 beta are seeing similar stricter codesigning validation behavior.

Answered by DTS Engineer in 887543022

Investigation suggests newer Xcode beta versions now reject additional extended attributes beyond com.apple.FinderInfo during codesigning.

That’s not right. This check is applied by the codesign tool, not by Xcode. The codesign tool is part of macOS, not part of the developer tools, so updates to Xcode don’t change this behaviour specifically. It’s possible that an update to your OS has changed this, but that’s unlikely. What’s more likely is that other parts of your build system are causing this problem.

Flutter tooling currently removes only: xattr -r -d com.apple.FinderInfo

This is the wrong way to resolve this issue.

Replacing it with: xattr -cr successfully resolves the issue.

And this is just doubling down on the wrong approach.

Rather, your should investigate what file has these extended attributes and how they got there. Once you have that information in hard, you can then takes steps to fix the root cause of these problems, rather than applying the xattr Band Aid™.

For example, I regularly see folks bump into issues like this because they’re storing their Xcode project in a weird location, like on iCloud Drive, and the correct fix is to not do that.

However, that’s just one example of a root cause, and there are many other ones. Which is why I recommended the above investigation on your side.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

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Answer 1

DTS Engineer OP

Apple

5h

Recommended

Investigation suggests newer Xcode beta versions now reject additional extended attributes beyond com.apple.FinderInfo during codesigning.

That’s not right. This check is applied by the codesign tool, not by Xcode. The codesign tool is part of macOS, not part of the developer tools, so updates to Xcode don’t change this behaviour specifically. It’s possible that an update to your OS has changed this, but that’s unlikely. What’s more likely is that other parts of your build system are causing this problem.

Flutter tooling currently removes only: xattr -r -d com.apple.FinderInfo

This is the wrong way to resolve this issue.

Replacing it with: xattr -cr successfully resolves the issue.

And this is just doubling down on the wrong approach.

Rather, your should investigate what file has these extended attributes and how they got there. Once you have that information in hard, you can then takes steps to fix the root cause of these problems, rather than applying the xattr Band Aid™.

For example, I regularly see folks bump into issues like this because they’re storing their Xcode project in a weird location, like on iCloud Drive, and the correct fix is to not do that.

However, that’s just one example of a root cause, and there are many other ones. Which is why I recommended the above investigation on your side.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

0