set-xcode-build-number step doesn't find info.plist

[h0shy]

We recently migrated our iOS project to use xcconfig files. Since then, the bitrise set-build-number step (2.0.4) throws the following error:

The version numbers are stored in the plist file. Run: key: string("INFOPLIST_FILE") not found in: serialized.Object(serialized.Object{})

Everything builds and runs fine locally, the path to the info.plist is correctly set in our xcconfig files and therefore in our build settings.

We cannot find any error on our side. Any advice would is much appreciated.