error: no type named 'transaction' in namespace 'eosio'

Question

During the tutorial on https://developers.eos.io/eosio-home/docs at the last step (step 2.9, the section about deferred transactions) when trying to compile the code, I get this error:

[*** addressbook]$ eosio-cpp -o addressbook.wasm addressbook.cpp -I ../abcounter/ -dI
warning: argument unused during compilation: '-dI' [-Wunused-command-line-argument]
/home/*****/eos/contracts/addressbook/addressbook.cpp:119:11: error: no type named 'transaction' in namespace 'eosio'
          eosio::transaction deferred;
          ~~~~~~~^
Warning, empty ricardian clause file
Warning, empty ricardian clause file
Warning, action <upsert> does not have a ricardian contract
Warning, action <erase> does not have a ricardian contract
Warning, action <notify> does not have a ricardian contract
1 error generated.
Error while processing /home/*****/eos/contracts/addressbook/addressbook.cpp.
abigen error

Why would there not be any eosio::transaction found? This should be part of the core cdt libraries, shouldn't it? Did I do something wrong when providing the library path?

Answer 1

I have found a solution, but I am unsure if this is the right way to do it.

The included files were under /usr/opt/eosio.cdt/1.6.1/include/eosiolib/contracts/eosio/ From there, it seems that the file transaction.hpp is included only in permission.hpp, but permission.hpp is not included anywhere:

[***** addressbook]$ grep -HiR "transaction.hpp" /usr/opt/eosio.cdt/1.6.1/include/eosiolib/contracts/eosio/
/usr/opt/eosio.cdt/1.6.1/include/eosiolib/contracts/eosio/permission.hpp:#include "transaction.hpp"
[***** addressbook]$ grep -HiR "permission.hpp" /usr/opt/eosio.cdt/1.6.1/include/eosiolib/contracts/eosio/
[***** addressbook]$

The tutorial's sample files all start with only #include <eosio/eosio.hpp>. Adding a line with #include <eosio/permission.hpp> makes compiling able to succeed, althogh there are now some warnings which were not there before:

In file included from /tmp/addressbook.cpp:1:
/usr/opt/eosio.cdt/1.6.1/bin/../include/eosiolib/contracts/eosio/permission.hpp:53:4: warning: control reaches end of non-void function [-Wreturn-type]
   }
   ^
/usr/opt/eosio.cdt/1.6.1/bin/../include/eosiolib/contracts/eosio/permission.hpp:78:4: warning: control reaches end of non-void function [-Wreturn-type]
   }
   ^