Qt project files and PREFIX variable

Question

I included

PREFIX = /usr/local

inside my project file and then I run

qmake myproject.pro

The makefile doesn't say anything about PREFIX though so I assume that i'm doing something wrong. Any ideas?

Solution 1

PREFIX doesn't mean anything in qmake files. The target for files is done via the target parameter. So if you want to make PREFIX determine the base location, such as /usr/local, you can do do something like this:

isEmpty(PREFIX) {
 PREFIX = /usr/local
}
TARGET = myapp
TARGET.path = $$PREFIX/

The isEmpty(PREFIX) will allow it to be changed during the command line call to qmake, e.g.

qmake PREFIX=/opt

Solution 2

That is INSTALL_ROOT variable on install, try
make install INSTALL_ROOT="your path"

Comments

[John Doe]

Why use the manually defined PREFIX variable when there is a standard INSTALL_ROOT for this? They serve the same purpose, don't they? Or maybe I'm missing something?

[Tatu Lahtela]

This allows you to change the default INSTALL_ROOT plus cross platform issues. You can look at this question for example for details. Note that this is almost a decade ago so times might have changed.