<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I forgot to say that I'm using this line in the Qt project to specify the include path:</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">INCLUDEPATH += /usr/include/coin</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Also I can successfully compile CLP projects with similar settings i.e.</div>LIBS += -L/usr/lib/x86_64-linux-gnu -lClp -lCoinUtils<br><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">INCLUDEPATH += /usr/include/coin</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">(and...)<br></div>#include "ClpSimplex.hpp"</div>