How to strip debug info from Microsoft.iOS.dll and others?

[rainbowcardiod]

I am trying to strip any debug info from all the dlls built within my dotnet project. I found that by adding the <DebugType>none</DebugType> and <DebugSymbols>false</DebugSymbols> properties to the project file I'm able to strip the main assembly of the project, but other debug info are still inside other assemblies (example: /Users/myuser/DotnetProject/obj/Release/net9.0-ios/ios-arm64/linked/Microsoft.iOS.pdb in Microsoft.iOS.dll).

There is some way to strip debug info also from the assemblies built within my project apart from the main one?

[vitek-karas]

@rolfbjarne would you know the answer?

[rolfbjarne]

The app bundle (in bin/Release/net9.0-ios/ios-arm64/*.app) won't contain any .pdb files. This is true even if you set <DebugType>portable</DebugType> (or don't change "DebugType" at all).

During the build process, pdb are used to create a dSYM bundle with native debug info that can be used to symbolicate crash reports, including managed frames. Removing pdb files from the build process will only result in poorer information in the dSYM bundle, which will lead to poorer symbolication of crash reports.

[rainbowcardiod]

I know that the app bundle doesn't contain any .pdb file, but I found that Microsoft.iOS.dll contains absolute paths of the machine I used for the build (ex: /Users/myuser/DotnetProject/obj/Release/net9.0-ios/ios-arm64/linked/Microsoft.iOS.pdb). So I would like to know how to strip these paths and possibly other private information from the bundle, debug info, and anything not strictly necessary to run the app.

[rolfbjarne]

There's no built in way to do this.

It might be possible to change the binaries yourself, just before they're signed, maybe using a command-line tool like sed:

$ sed 's_/Users/myuser/              _g/' path/to/myapp.app/Microsoft.iOS.dll > tmp
$ mv tmp path/to/myapp.app/Microsoft.iOS.dll

Note that it's very important to not remove or add any characters, only replace (with space in this case).

You could add it to the build by executing a target before the app is signed, by adding something like this to your csproj:

<Target Name="ErasePrivateInfo" BeforeTargets="BeforeCodesign" >
    <Exec Command="erase-private-info.sh $(AppBundleDir)" />
</Target>

and then the script:

#!/bin/bash -e

AppBundleDir=$1

sed 's_/Users/myuser/              _g/' $AppBundleDir/Microsoft.iOS.dll > /tmp/Microsoft.iOS.dll.tmp
mv /tmp/Microsoft.iOS.dll.tmp $AppBundleDir/Microsoft.iOS.dll

# add more replacements here

I'm using an external script because it's much easier to get any quoting correct. It's also easier to test the script outside of building your project (you can use any scripting language you want, powershell for instance might be a viable alternative).