Package QtWidgets was not found in the pkg-config search path.

[lthiet]

Hello.

I follow the documentation for compiling. Just didn't do the Collada thing. http://mitsuba-renderer.org/docs.html.

Instead of installing libpng12-dev I installed libpng-dev, and instead of libpcrecpp0 I installed libpcrecpp0v5. I haven't modified my local repo.

After running scons ,here's the error message I have :

scons: Reading SConscript files ...
Using configuation file "/home/lam/work/ext/mitsuba/config.py"
Checking for Qt 5.x... yes
Checking for g++ ...yes
Checking for C header file png.h... yes
Checking for C header file jpeglib.h... yes
Checking for C++ header file ImfRgba.h... yes
Checking for C++ header file xercesc/dom/DOMLSParser.hpp... yes
Checking for C++ header file dae.h... no
COLLADA DOM is missing: not building the COLLADA importer
Checking for C++ header file pyconfig.h... yes
Checking for C++ header file pyconfig.h... yes
Checking for C++ header file boost/version.hpp... yes
Checking for C++ header file Eigen/Core... yes
Checking for C++ header file fftw3.h... yes
Checking for C header file GL/gl.h... yes
Checking for C header file GL/glu.h... yes
Checking for C header file GL/glext.h... yes
Checking for C header file GL/glew.h... yes
Checking for C type GLEWContext... yes
Checking for C header file X11/extensions/xf86vmode.h... yes
Checking for Mitsuba version .. 0.6.0
Package QtWidgets was not found in the pkg-config search path.
Perhaps you should add the directory containing `QtWidgets.pc'
to the PKG_CONFIG_PATH environment variable
No package 'QtWidgets' found
OSError: 'pkg-config QtGui QtWidgets QtCore QtOpenGL QtXml QtXmlPatterns QtNetwork --libs --cflags' exited 1:
  File "/home/lam/work/ext/mitsuba/SConstruct", line 54:
    build('src/mtsgui/SConscript', ['mainEnv', 'converter_objects'], duplicate=True)
  File "/home/lam/work/ext/mitsuba/SConstruct", line 29:
    variant_dir=os.path.join(env['BUILDDIR'], dirname), duplicate=duplicate)
  File "/usr/lib/scons/SCons/Script/SConscript.py", line 614:
    return method(*args, **kw)
  File "/usr/lib/scons/SCons/Script/SConscript.py", line 551:
    return _SConscript(self.fs, *files, **subst_kw)
  File "/usr/lib/scons/SCons/Script/SConscript.py", line 256:
    call_stack[-1].globals)
  File "/home/lam/work/ext/mitsuba/build/release/mtsgui/SConscript", line 28:
    qtEnv.EnableQt5Modules(['QtGui', 'QtWidgets', 'QtCore', 'QtOpenGL', 'QtXml', 'QtXmlPatterns', 'QtNetwork'])
  File "/usr/lib/scons/SCons/Environment.py", line 224:
    return self.method(*nargs, **kwargs)
  File "/home/lam/work/ext/mitsuba/data/scons/qt5.py", line 449:
    self.ParseConfig('pkg-config %s --libs --cflags'% ' '.join(pcmodules))
  File "/usr/lib/scons/SCons/Environment.py", line 1557:
    return function(self, self.backtick(command))
  File "/usr/lib/scons/SCons/Environment.py", line 594:
    raise OSError("'%s' exited %d" % (command, status))

It seems issue #32 is similar, but has apparently been fixed by #38.

From another project, I know that QtWidgets is located here : /usr/lib/x86_64-linux-gnu/cmake/Qt5Widgets so I added this line to my .bashrc : export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/lib/x86_64-linux-gnu/cmake/Qt5Widgets

But the error persists. I'm not quite sure what else to do. I have had many problems with Qt before... Any help would be appreciated!

[adnphllps]

Since qt changed their naming to include the version, one fix is to cd into your pkgconfig directory (maybe /usr/lib/x86_64-linux-gnu/pkgconfig) make sure the file Qt5Widgets is there, then run:
sudo ln -s ./Qt5Widgets.pc ./QtWidgets.pc

[dsvilarkovic]

This issue happened to me as well, and I followed @adnphllps instructions, since it didn't work for any Qt related file before.
Thing I did was: find pkg-config using find / -type d -name "pkgconfig" 2>/dev/null, and looked for the most relevant path with Qt inside and then I entered in my case cd /usr/lib/x86_64-linux-gnu/pkgconfig. From there I listed using ls Qt* and got:
Qt5Concurrent.pc Qt5Core.pc Qt5DBus.pc Qt5Gui.pc Qt5Network.pc Qt5OpenGLExtensions.pc Qt5OpenGL.pc Qt5PrintSupport.pc Qt5Sql.pc Qt5Test.pc Qt5Widgets.pc Qt5XmlPatterns.pc Qt5Xml.pc
As you can see, everything now is named as Qt<version_number><file_name> (i.e. Qt5Core) instead of Qt<file_name> (i.e. QtCore) as scons is expecting it.
In order to overcome this problem I used symbolic link in the same way as @adnphllps did:
sudo ln -s ./Qt5Core.pc ./QtCore.pc for every single file_name there, and finally resolved my issue.

[kushal123478]

@dsvilarkovic Your approach worked well for me thanks.