Build system doesn’t notice source changes #3955

1. 
   luke-jr commented at 3:16 am on March 25, 2014: member

   To reproduce:

   • make src/bitcoind
   • touch src/checkpoints.cpp
   • make src/bitcoind # notice it doesn’t rebuild anything
2. laanwj added the label Build system on Mar 25, 2014
3. 
   rebroad commented at 11:49 pm on April 7, 2014: contributor

   #3989 - moving away from a recursive Makefile may be the solution to this.
4. 
   laanwj commented at 10:45 am on April 8, 2014: member

   Just that you have a hammer (woohoo! non-recursive makefiles!) doesn’t mean that everything is a nail.

   As this involves two files in the same directory it should be perfectly possible to get this right with the current build system.

5. 
   rebroad commented at 8:08 am on May 2, 2014: contributor

   So.. what is the way forwards with this? If I can get a better idea I can at least know where I need to extend my knowledge for helping to find a solution. If it’s not non-recursive Makefiles, then what is it?
6. 
   Diapolo commented at 8:11 am on May 2, 2014: none

   Perhaps dumb, but why isn’t a simple hash of a source file used and if that differs we trigger a clean and a normal make for example?
7. 
   laanwj commented at 9:17 am on May 2, 2014: member

   I see I was wrong above: I didn’t notice the src/ before the targets passed to make. This is building an executable in another directory.

   The following make rule is triggered: https://github.com/bitcoin/bitcoin/blob/master/Makefile.am#L56 Notice that there are no dependencies specified. If the executables exist at all, make will assume rule is satisfied. Specifying them as phony targets may be one solution here: https://www.gnu.org/software/make/manual/html_node/Phony-Targets.html .

8. theuni referenced this in commit 77a055d049 on Jun 11, 2014
9. laanwj closed this on Jun 11, 2014

   ---

10. wtogami referenced this in commit 406e6616b6 on Sep 19, 2014
11. wtogami referenced this in commit 9f8b82a94f on Oct 2, 2014
12. MathyV referenced this in commit 9d50a62197 on Nov 3, 2014
13. wtogami referenced this in commit 9128bea913 on Nov 14, 2014
14. wtogami referenced this in commit d3f90baedc on Dec 23, 2014
15. reddink referenced this in commit 85faa5d4f6 on May 27, 2020
16. MarcoFalke locked this on Sep 8, 2021

Contributors
luke-jr rebroad laanwj Diapolo

Labels
Build system