# Build error

**URL:** <https://www.ruby-forum.com/t/build-error/239515>\
**Category:** GNU Radio\
**Created:** [March 3, 2014, 2:50am UTC](https://www.ruby-forum.com/t/build-error/239515 "2014-03-03T02:50:12Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Detlef\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/58f4c7/32.png) [@Detlef\_R](https://www.ruby-forum.com/u/Detlef_R)\
**Post date:** [March 3, 2014, 2:50am UTC](https://www.ruby-forum.com/t/build-error/239515/1 "2014-03-03T02:50:12Z")

</div>

hi,  
when i install a new block ,try “make”,i got these errors:  
CMakeFiles/test-scramble.dir/test\_scramble.cc.o: In function  
`boost::filesystem::operator/(boost::filesystem::path const&, boost::filesystem::path const&)': test_scramble.cc:(.text._ZN5boost10filesystemdvERKNS0_4pathES3_[boost::filesystem::operator/(boost::filesystem::path const&, boost::filesystem::path const&)]+0x29): undefined reference to`boost::filesystem::path::operator/=(boost::filesystem::path const&)’  
CMakeFiles/test-scramble.dir/test\_scramble.cc.o: In function `main': test_scramble.cc:(.text.startup+0x8a): undefined reference to`boost::filesystem::detail::current\_path(boost::system::error\_code\*)’  
test\_scramble.cc:(.text.startup+0xdc): undefined reference to  
`boost::filesystem::detail::status(boost::filesystem::path const&, boost::system::error_code*)' test_scramble.cc:(.text.startup+0xf8): undefined reference to`boost::filesystem::detail::create\_directory(boost::filesystem::path  
const&, boost::system::error\_code\*)’

what does this mean?how to solve it?  
BZS

---

<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [March 3, 2014, 3:35am UTC](https://www.ruby-forum.com/t/build-error/239515/2 "2014-03-03T03:35:30Z")

</div>

BZS,

This error indicates that you aren’t linking against the boost  
filesystem  
library.

In the CMakeLists.txt file within the “lib” directory of the custom  
block,  
there will be a section that looks similar to this:

target\_link\_libraries(  
${GNURADIO\_RUNTIME\_LIBRARIES}

)

This indicates that

---

<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [March 3, 2014, 3:36am UTC](https://www.ruby-forum.com/t/build-error/239515/3 "2014-03-03T03:36:41Z")

</div>

(please excuse the previous incomplete message)

You will need to update the target\_link\_libraries section to add the  
following:

${Boost\_FILESYSTEM\_LIBRARY}

This will link against the boost filesystem library and resolve the  
error  
you’re receiving.

- Marc