# Double Conversion Error
**URL:** https://discourse.itk.org/t/double-conversion-error/5172
**Category:** Beginner Questions
**Tags:** cmake
**Created:** [July 8, 2022, 7:49pm UTC](https://discourse.itk.org/t/double-conversion-error/5172 "2022-07-08T19:49:58Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@haochenz58](https://discourse.itk.org/u/haochenz58)
#### Post date: [July 8, 2022, 7:49pm UTC](https://discourse.itk.org/t/double-conversion-error/5172/1 "2022-07-08T19:49:58Z")
Hi! I’m trying to build and run my ITK from source on Ubuntu 20.04. I pulled from the repo, used cmake to configure and generate it, then ran the example/installation hello world example with a separate build folder under /bin. It gave me the following output and error:
– Configuring done
– Generating done
– Build files have been written to: /home/haochenz/ITK/Examples/Installation/bin
Scanning dependencies of target HelloWorld
[50%] Building CXX object CMakeFiles/HelloWorld.dir/HelloWorld.cxx.o
make[2]: \*\*\* No rule to make target ‘/home/haochenz/ITK-build/lib/libitkdouble-conversion-5.3.a’, needed by ‘HelloWorld’. Stop.
make[1]: \*\*\* [CMakeFiles/Makefile2:76: CMakeFiles/HelloWorld.dir/all] Error 2
make: \*\*\* [Makefile:84: all] Error 2
It seems that it need double-conversion. This error have not occurred previously when I was on Windows. I tried to turn on the ITK\_USE\_SYSTEM\_DOUBLECONVERSIO option in cmake and it generated more errors regarding the doubleconversion. I looked into the past discussion and github issues, don’t think they are particularly helpful in my case. I’m not sure what to do rn, any help would be great!
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### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [July 8, 2022, 7:58pm UTC](https://discourse.itk.org/t/double-conversion-error/5172/2 "2022-07-08T19:58:03Z")
Which version of ITK are you using? Try `master` or `v5.3rc3`.
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### Author:  [@haochenz58](https://discourse.itk.org/u/haochenz58)
#### Post date: [July 8, 2022, 8:04pm UTC](https://discourse.itk.org/t/double-conversion-error/5172/3 "2022-07-08T20:04:27Z")
I’m sure I’m currently on Master
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### Author:  [@dzenanz](https://discourse.itk.org/u/dzenanz)
#### Post date: [July 8, 2022, 8:38pm UTC](https://discourse.itk.org/t/double-conversion-error/5172/4 "2022-07-08T20:38:38Z")
I haven’t built on Linux for a few weeks now, but I do have 20.04. Could you provide repro steps, such as exact configure command? I do see you have examples enabled.
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### Author:  [@haochenz58](https://discourse.itk.org/u/haochenz58)
#### Post date: [July 12, 2022, 5:54pm UTC](https://discourse.itk.org/t/double-conversion-error/5172/5 "2022-07-12T17:54:31Z")
MyB I found out a very dumb error. I directly included the ITK build folder pth in cmake configuration without making in the build directory first. That must be it