Makefile dependencies broken by autotools? #3070

So I compiled in my master branch, then checked out my 'smartfee' branch and re-compiled, and get:

Undefined symbols for architecture x86_64:
  "CTransaction::nMinRelayTxFee", referenced from:
      PaymentServer::processPaymentRequest(PaymentRequestPlus&, QList<SendCoinsRecipient>&) in libbitcoinqt.a(libbitcoinqt_a-paymentserver.o)

Indeed, CTransaction::nMinRelayTxFee is gone in the smartfee branch. But why didn't the new autotools make figure that out?

Workaround is to do a 'make clean', but dependencies should work properly or we'll spend a lot of time tracking down bugs that go away if we make clean and then recompile.

"make clean" works because it regenerates the makefiles from scratch.

https://www.flameeyes.eu/autotools-mythbuster/automake/maintainer.html This may be relevant.

It sounds like you want make to detect that it needs to regenerate its own rules. I'm uncertain if that will play nice with faketime in gitian?

#3989 - it's been suggested that moving away from recursive Makefiles is the best solution.

As we're moving towards more modularized source trees, we'll need a solution for interdependencies anyway, I guess? (autotools noob here)

#4118 is a relative to this issue.

@rebroad can you please stop pimping your issue everywhere; if you have a solution, that's great, but refering to another issue where the problem is re-stated is not constructive.

Fixed-- I'm a happy camper.