Permanent Build Error with openCVaddonn

hi :wink:
but i found a persistent error in buidling up the project i get :

[Build Error] No rule to make target ‘pp’ needed by ‘obj/ofCvColorImage.o’.

if i REBUILD ALL the project it always work. But i never can make it compile and link if it’s not a rebuild …

with devC++ i’ve already found sometimes the necessity of rebuilding all, but usually once u’ve done it u could then compile normally, and this case seems different, more consistent …

any ideas ?


I don’t know, dev-c++ is pretty gnarly, but I haven’t seen that and we were just working with a bunch of people in madrid (at interactivos) that used dev-c++ without that problem.

I have seen the occasional recompile all thing, that is because dev-c++ is really really bad at knowing when the code has changed enough to recompile objects, so that sometimes you get old objects and new ones mingling together, causing bizzare behavior and crashes. I take it as a quirck, and one of the side effects of using free software.

If it happens always, then I think you need to try again every step and see if it goes away. If not, let us know something about the OS - xp/spanish, etc. so we can start to diagnose better why it is happening to you.

so, can I ask you to try again:

a) downloading of 0.02 and the addon and doing it again…

if it still happens:

b) download and reinstall dev-c++ then step a

good luck!!

ok - I think I know what this is now…

I never saw it, because I always had checked:

tools -> compilers -> use fast but imperfect makefile generation

when you turn that off, you get the ‘pp’ target problem.

after playing with it for several hours yesterday, I learned that the length of the relative path presents a problem. for example, this:


gives issues when the fast but imperfect generation is turned off. it messes up the makefile generation somehow. I don’t know why, but is makes the makefile like this:

obj/ofCvGrayscaleI.o: ../../libs/openFrameworks/cvthisisalongasfoldernameyo/ofCvGrayscaleImage.cpp pp    

thus the ‘pp’ issue…

when you use a short path:


this will compile fine…

(actually cv/ofCvGrayscaleImage.cpp is about on character too long, but it compiles fine when I shorten that)

obviously this is a huge pain, especially with addons. I’m going to test it a bit more so I know what the limits are…

it appears that this problem is based on path length + “use fast but imperfect makefile generation” being turned off.

take care!

ps : seeing this renewed our interest in discovering some pc alternatives, like code::blocks or eclipse… for now, we will continue to support devcpp, but this is a pretty nasty problem for us, since our addon paths can be quite long…