I followed the instructions at https://chromium.googlesource.com/chromium/src/+/master/tools/binary_size/README.md to generate a supersize report on Linux.

When I built the chrome binary and passed it to supersize archive, it complained with "Could not find .map(.gz)? file. Ensure you have built with is_official_build=true, or use --map-file to point me a linker map file".

I built again with is_official_build=true but apparently that's not enough either, I also needed generate_linker_map=true.

It would be nice if either the instructions or supersize.py mention this.