Qt 5 migration - Cannot open include file: 'ui_mainwindow.h'

Question

I\'m trying to migrate a simple project to Qt 5. The project was originally written for Qt 4, and it compiles fine there.

When compiling with Qt 5, however, I\'m get

Answer 1

I had the same problem; solved cleaning the project (From Qt->Build) and adding:

SET(CMAKE_INCLUDE_CURRENT_DIR ON)

As an example, this is my CMakeLists.txt working well:

#Specify the minimum version of CMake (3.1 is currently recommended by Qt)
cmake_minimum_required(VERSION 3.1)

# Specify project title
project(challenge_MarcoRuiz)

# To automatically run MOC when building (Meta Object Compiler)
set(CMAKE_AUTOMOC ON)

# To automatically run UIC when building (User Interface Compiler)
set(CMAKE_AUTOUIC ON)

# To automatically run RCC when building (Resource Compiler)
set(CMAKE_AUTORCC ON)

# Specify OpenCV folder, and take care of dependencies and includes
find_package(OpenCV REQUIRED)
include_directories(${OpenCV_INCLUDE_DIRS})

# Take care of Qt dependencies
find_package(Qt5 COMPONENTS Core Gui Widgets REQUIRED)

## 
SET(CMAKE_INCLUDE_CURRENT_DIR ON)

# add required source, header, ui and resource files
add_executable(${PROJECT_NAME} "main.cpp" "mainwindow.h" "mainwindow.cpp" "mainwindow.ui" ${UI_HEADERS})

# link required libs
target_link_libraries(${PROJECT_NAME} Qt5::Core Qt5::Gui Qt5::Widgets ${OpenCV_LIBS} ${UI_HEADERS})