const&)’
/usr/local/lib/libITKCommon-5.1.a(itkDirectory.cxx.o): In function `itk::Directory::PrintSelf(std::ostream&, itk::Indent) const': itkDirectory.cxx:(.text+0x26a): undefined reference to`itksys::Directory::GetPath() const’
itkDirectory.cxx:(.text+0x2d5): undefined reference to `itksys::Directory::GetNumberOfFiles() const' itkDirectory.cxx:(.text+0x337): undefined reference to`itksys::Directory::GetFile(unsigned long) const’
/usr/local/lib/libITKCommon-5.1.a(itkDirectory.cxx.o): In function `itk::Directory::GetNumberOfFiles()': itkDirectory.cxx:(.text+0x205): undefined reference to`itksys::Directory::GetNumberOfFiles() const’
/usr/local/lib/libITKCommon-5.1.a(itkDirectory.cxx.o): In function `itk::Directory::GetFile(unsigned int)': itkDirectory.cxx:(.text+0x217): undefined reference to`itksys::Directory::GetFile(unsigned long) const’
collect2: error: ld returned 1 exit status
make: \*\*\* […/yyy] Error 1
23:00:12: Le processus “/usr/bin/make” s’est terminé avec le code 2.
Erreur lors de la compilation/déploiement du projet magicsIMNC (kit : Desktop Qt 5.12.5 GCC 64bit)
When executing step “Make”
The command is
g++ -Wl,-O1 -o …/yyy list-of-myfiles.o -L/usr/local/lib -litkdouble-conversion-5.1 -litknetlib-5.1 -lITKOptimizers-5.1 -litkvnl\_algo-5.1 -litkvnl-5.1 -lITKVNLInstantiation-5.1 -lITKOptimizersv4-5.1 -lITKStatistics-5.1 -litkv3p\_netlib-5.1 -litksys-5.1 -lITKCommon-5.1 -ldl -lpthread /home/xxx/Qt/5.12.5/gcc\_64/lib/libQt5PrintSupport.so /home/xxx/Qt/5.12.5/gcc\_64/lib/libQt5Widgets.so /home/xxx/Qt/5.12.5/gcc\_64/lib/libQt5Gui.so /home/xxx/Qt/5.12.5/gcc\_64/lib/libQt5Concurrent.so /home/xxx/Qt/5.12.5/gcc\_64/lib/libQt5Core.so -lGL
---
### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [November 15, 2019, 8:06pm UTC](https://discourse.itk.org/t/linking-itk-and-qt-ubuntu/2415/2 "2019-11-15T20:06:27Z")
You could take a look at this [discussion](https://discourse.itk.org/t/double-conversion-problem-in-vcpkg-build/1486), as well as this [PR](https://github.com/microsoft/vcpkg/pull/5115) which has more references to code.
---
### Author:  [@FBT](https://discourse.itk.org/u/FBT)
#### Post date: [November 18, 2019, 9:51am UTC](https://discourse.itk.org/t/linking-itk-and-qt-ubuntu/2415/3 "2019-11-18T09:51:57Z")
Thank you for your answer.
```
I saw this topic but my problem is not the include file
```
“double-conversion.h” at the compilation step. My problem is at
the linking step : all the itk libraries are built without any
problem, the itk tests are OK, but when linking my qt project
with the itk libraries, I got the errors listed in my previous
post.
---
### Author:  [@phcerdan](https://discourse.itk.org/u/phcerdan)
#### Post date: [November 18, 2019, 11:15am UTC](https://discourse.itk.org/t/linking-itk-and-qt-ubuntu/2415/4 "2019-11-18T11:15:02Z")
Hi @FBT, you are not using `CMake`.
From where did you get the list of ITK libraries that you need? Maybe you are missing some? Have you tried to link all of them? Did you compile ITK with default options, or used any `SYSTEM` library?
The Common module seems to have more dependencies that you have used. See its [itk-module.cmake](https://github.com/InsightSoftwareConsortium/ITK/blob/master/Modules/Core/Common/itk-module.cmake)
```auto
if( Module_ITKTBB )
set(ITKCOMMON_TBB_DEPENDS ITKTBB)
endif()
itk_module(ITKCommon
ENABLE_SHARED
DEPENDS
ITKEigen3
ITKKWIML
${ITKCOMMON_TBB_DEPENDS}
PRIVATE_DEPENDS
ITKDoubleConversion
COMPILE_DEPENDS
ITKKWSys
ITKVNLInstantiation
TEST_DEPENDS
ITKTestKernel
ITKMesh
ITKImageIntensity
ITKIOImageBase
DESCRIPTION
"${DOCUMENTATION}"
)
```
---
### Author:  [@FBT](https://discourse.itk.org/u/FBT)
#### Post date: [November 18, 2019, 12:24pm UTC](https://discourse.itk.org/t/linking-itk-and-qt-ubuntu/2415/5 "2019-11-18T12:24:46Z")
I compiled ITK with cmake-gui 3.10.2 . I kept the default
options, I just add Module\_ITKreview .
```
My own program is compiled with Qt-creator and is configured in a
```
.pro file. Yes, I tried to include all libraries, in that case I
get other errors (listed below). I 've done such a way on windows
for a long time and everything works fine.
```
/usr/local/lib/libITKOptimizers-5.1.a(itkMultipleValuedNonLinearVnlOptimizer.cxx.o):
```
In function
`itk::MultipleValuedNonLinearVnlOptimizer::PrintSelf(std::ostream&,
itk::Indent) const’:
```
itkMultipleValuedNonLinearVnlOptimizer.cxx:(.text+0x4d):
```
undefined reference to `std::ostream& itk::operator\<\<
(std::ostream&, itk::Array
const&)’
```
itkMultipleValuedNonLinearVnlOptimizer.cxx:(.text+0xbb):
```
undefined reference to `std::ostream& itk::operator\<\<
(std::ostream&, itk::Array2D
const&)’
```
itkMultipleValuedNonLinearVnlOptimizer.cxx:(.text+0x129):
```
undefined reference to `std::ostream& itk::operator\<\<
(std::ostream&, itk::Array
const&)’
```
/usr/local/lib/libITKOptimizers-5.1.a(itkMultipleValuedNonLinearVnlOptimizer.cxx.o):
```
In function
`itk::MultipleValuedNonLinearVnlOptimizer::MultipleValuedNonLinearVnlOptimizer()’:
```
itkMultipleValuedNonLinearVnlOptimizer.cxx:(.text+0x569):
```
undefined reference to `itk::Command::Command()’
```
/usr/local/lib/libITKOptimizers-5.1.a(itkMultipleValuedNonLinearVnlOptimizer.cxx.o):
```
In function
`itk::ReceptorMemberCommanditk::MultipleValuedNonLinearVnlOptimizer::~ReceptorMemberCommand()’:
```
itkMultipleValuedNonLinearVnlOptimizer.cxx:(.text._ZN3itk21ReceptorMemberCommandINS_35MultipleValuedNonLinearVnlOptimizerEED2Ev[_ZN3itk21ReceptorMemberCommandINS_35MultipleValuedNonLinearVnlOptimizerEED5Ev]+0xf):
```
undefined reference to `itk::Command::~Command()’
```
/usr/local/lib/libITKOptimizers-5.1.a(itkMultipleValuedNonLinearVnlOptimizer.cxx.o):
```
In function
`itk::ReceptorMemberCommanditk::MultipleValuedNonLinearVnlOptimizer::~ReceptorMemberCommand()’:
```
itkMultipleValuedNonLinearVnlOptimizer.cxx:(.text._ZN3itk21ReceptorMemberCommandINS_35MultipleValuedNonLinearVnlOptimizerEED0Ev[_ZN3itk21ReceptorMemberCommandINS_35MultipleValuedNonLinearVnlOptimizerEED5Ev]+0x13):
```
undefined reference to `itk::Command::~Command()’
```
/usr/local/lib/libITKOptimizers-5.1.a(itkMultipleValuedNonLinearVnlOptimizer.cxx.o):
```
In function
`itk::ReceptorMemberCommanditk::MultipleValuedNonLinearVnlOptimizer::CreateAnother()
const’:
```
itkMultipleValuedNonLinearVnlOptimizer.cxx:(.text._ZNK3itk21ReceptorMemberCommandINS_35MultipleValuedNonLinearVnlOptimizerEE13CreateAnotherEv[_ZNK3itk21ReceptorMemberCommandINS_35MultipleValuedNonLinearVnlOptimizerEE13CreateAnotherEv]+0xdb):
```
undefined reference to `itk::Command::Command()’
```
/usr/local/lib/libITKOptimizers-5.1.a(itkMultipleValuedNonLinearVnlOptimizer.cxx.o):(.data.rel.ro._ZTIN3itk21ReceptorMemberCommandINS_35MultipleValuedNonLinearVnlOptimizerEEE[_ZTIN3itk21ReceptorMemberCommandINS_35MultipleValuedNonLinearVnlOptimizerEEE]+0x10):
```
undefined reference to `typeinfo for itk::Command’
```
/usr/local/lib/libITKOptimizers-5.1.a(itkOptimizer.cxx.o):
```
In function `itk::Optimizer::PrintSelf(std::ostream&,
itk::Indent) const’:
```
itkOptimizer.cxx:(.text+0x11fd):
```
undefined reference to `std::ostream& itk::operator\<\<
(std::ostream&, itk::Array
const&)’
```
itkOptimizer.cxx:(.text+0x1266):
```
undefined reference to `std::ostream& itk::operator\<\<
(std::ostream&, itk::Array
const&)’
```
itkOptimizer.cxx:(.text+0x13e7):
```
undefined reference to `std::ostream& itk::operator\<\<
(std::ostream&, itk::Array
const&)’
```
itkOptimizer.cxx:(.text+0x1453):
```
undefined reference to `std::ostream& itk::operator\<\<
(std::ostream&, itk::Array
const&)’
```
/usr/local/lib/libitkvnl_algo-5.1.a(vnl_levenberg_marquardt.cxx.o):
```
In function `vnl\_levenberg\_marquardt::lmdif\_lsqfun(long\*, long\*,
double\*, double\*, long\*, void\*)’:
```
vnl_levenberg_marquardt.cxx:(.text+0x9f):
```
undefined reference to
`vnl\_vector\_ref::vnl\_vector\_ref(unsigned int,
double\*)’
```
vnl_levenberg_marquardt.cxx:(.text+0xb8):
```
undefined reference to
`vnl\_vector\_ref::vnl\_vector\_ref(unsigned int,
double\*)’
```
vnl_levenberg_marquardt.cxx:(.text+0x109):
```
undefined reference to
`vnl\_vector\_ref::~vnl\_vector\_ref()’
```
vnl_levenberg_marquardt.cxx:(.text+0x111):
```
undefined reference to
`vnl\_vector\_ref::~vnl\_vector\_ref()’
```
vnl_levenberg_marquardt.cxx:(.text+0x2d7):
```
undefined reference to
`vnl\_vector\_ref::~vnl\_vector\_ref()’
```
vnl_levenberg_marquardt.cxx:(.text+0x2df):
```
undefined reference to
`vnl\_vector\_ref::~vnl\_vector\_ref()’
```
/usr/local/lib/libitkvnl_algo-5.1.a(vnl_levenberg_marquardt.cxx.o):
```
In function `vnl\_levenberg\_marquardt::lmder\_lsqfun(long\*, long\*,
double\*, double\*, double\*, long\*, long\*, void\*)’:
```
vnl_levenberg_marquardt.cxx:(.text+0x36a):
```
undefined reference to
`vnl\_vector\_ref::vnl\_vector\_ref(unsigned int,
double\*)’
```
vnl_levenberg_marquardt.cxx:(.text+0x386):
```
undefined reference to
`vnl\_vector\_ref::vnl\_vector\_ref(unsigned int,
double\*)’
```
vnl_levenberg_marquardt.cxx:(.text+0x55b):
```
undefined reference to
`vnl\_vector\_ref::~vnl\_vector\_ref()’
```
vnl_levenberg_marquardt.cxx:(.text+0x567):
```
undefined reference to
`vnl\_vector\_ref::~vnl\_vector\_ref()’
```
vnl_levenberg_marquardt.cxx:(.text+0x69a):
```
undefined reference to `v3p\_netlib\_fdjac2\_’
```
vnl_levenberg_marquardt.cxx:(.text+0xa6d):
```
undefined reference to
`vnl\_vector\_ref::~vnl\_vector\_ref()’
```
vnl_levenberg_marquardt.cxx:(.text+0xa79):
```
undefined reference to
`vnl\_vector\_ref::~vnl\_vector\_ref()’
```
/usr/local/lib/libitkvnl_algo-5.1.a(vnl_levenberg_marquardt.cxx.o):
```
In function
`vnl\_levenberg\_marquardt::minimize\_without\_gradient(vnl\_vector&)’:
```
vnl_levenberg_marquardt.cxx:(.text+0xec6):
```
undefined reference to `v3p\_netlib\_lmdif\_’
```
/usr/local/lib/libitkvnl_algo-5.1.a(vnl_levenberg_marquardt.cxx.o):
```
In function
`vnl\_levenberg\_marquardt::minimize\_using\_gradient(vnl\_vector&)’:
```
vnl_levenberg_marquardt.cxx:(.text+0x12b7):
```
undefined reference to `v3p\_netlib\_lmder\_’
```
/usr/local/lib/libitkvnl_algo-5.1.a(vnl_levenberg_marquardt.cxx.o):
```
In function `vnl\_levenberg\_marquardt::get\_JtJ()’:
```
vnl_levenberg_marquardt.cxx:(.text+0x19ca):
```
undefined reference to
`vnl\_fastops::AtA(vnl\_matrix&,
vnl\_matrix const&)’
```
vnl_levenberg_marquardt.cxx:(.text+0x19ec):
```
undefined reference to `vnl\_vector::vnl\_vector(unsigned
long)’
```
vnl_levenberg_marquardt.cxx:(.text+0x1ac0):
```
undefined reference to `vnl\_vector::~vnl\_vector()’
```
vnl_levenberg_marquardt.cxx:(.text+0x1b39):
```
undefined reference to `vnl\_vector::~vnl\_vector()’
```
/usr/local/lib/libitkvnl_algo-5.1.a(vnl_levenberg_marquardt.cxx.o):
```
In function `\_GLOBAL\_\_sub\_I\_vnl\_levenberg\_marquardt.cxx’:
```
vnl_levenberg_marquardt.cxx:(.text.startup+0x2f):
```
undefined reference to `v3p\_netlib\_initialize’
```
collect2: error:
```
ld returned 1 exit status
---
### Author:  [@phcerdan](https://discourse.itk.org/u/phcerdan)
#### Post date: [November 18, 2019, 12:43pm UTC](https://discourse.itk.org/t/linking-itk-and-qt-ubuntu/2415/6 "2019-11-18T12:43:41Z")
Are you sure those ITK libraries are up-to-date? Could you remove them all and recompile and reinstall ITK? Or maybe install ITK in another location and try from there? Maybe the order of the ITK libraries play a role?
I am not familiar with Qt `.pro` projects, but there a lot of other projects using Qt and ITK (using `CMake`) with no issues. I’d recommend to start in a clean state with ITK, and sorry for the long-shot suggestions, not familiar with `.pro` files, I would finally recommend you try a toy project with CMake, Qt and ITK to check if it works.
---
### Author:  [@FBT](https://discourse.itk.org/u/FBT)
#### Post date: [November 18, 2019, 12:58pm UTC](https://discourse.itk.org/t/linking-itk-and-qt-ubuntu/2415/7 "2019-11-18T12:58:27Z")
Thank you for the suggestions. I download and compiled ITK a few
days ago so I’m sure they are up-to-date. I tried several times,
with and without ITKreview. I develop the project on windows using
Qtcreator and I would like to use the same tools on both systems,
it works on windows, it should on ubuntu.