How to symbolicate crash log Xcode?

Writing this answer as much for the community as for myself.

If there ever are problems symbolicating a crash report, one can overcome them as follows:

1. Create a separate folder, copy Foo.app and Foo.app.dSYM from the corresponding .xcarchive into the folder. Also copy the .crash report into the folder.

2. Open the crash report in TextEdit or elsewhere, go to the Binary Images: section, and copy the first address there (e.g. 0xd7000).

3. cd into the folder. Now you can run the following command:

   xcrun atos -o Foo.app/Foo -arch arm64 -l 0xd7000 0x0033f9bb

This will symbolicate the symbol at address 0x0033f9bb. Please make sure to pick the correct value for the -arch option (can be obtaned from the first line in the Binary Images: section, or figured out from the Hardware Model: in the crash report and the app’s supported archs).

You can also copy the necessary addresses (e.g. a thread call stack) from the crash report directly into a text file (in TextEdit, hold Option and select the necessary text block, or copy and cut), to get something like this:

0x000f12fb
0x002726b7
0x0026d415
0x001f933b
0x001f86d3

Now you can save this into a text file, e.g. addr.txt, and run the following command:

xcrun atos -o Foo.app/Foo -arch arm64 -l 0xd7000 -f addr.txt

This will give a nice symbolication for all the addresses at once.

P.S.

Before doing the above, it’s worth checking that everything is set up correctly (as atos will happily report something for basically any supplied address).

To do the checking, open the crash report, and go to the end of the call stack for Thread 0. The first line from the end to list your app (usually the second one), e.g.:

34  Foo                    0x0033f9bb 0xd7000 + 2525627

should be the main() call. Symbolicating the address (0x0033f9bb in this case) as described above should confirm that this is indeed main() and not some random method or function.

If the address is not that of main(), check your load address (-l option) and arch (-arch option).

P.P.S.

If the above doesn’t work due to bitcode, download the dSYM for your build from iTunes Connect, extract the executable binary from the dSYM (Finder > Show Package Contents), copy it into the directory, and use it (i.e. Foo) as the argument to atos, instead of the Foo.app/Foo.