# Howto\_square\_ff require Gruel **URL:** \ **Category:** GNU Radio\ **Created:** [November 8, 2012, 6:34pm UTC](https://www.ruby-forum.com/t/howto-square-ff-require-gruel/224355 "2012-11-08T18:34:38Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![aris](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/258eb7/32.png) [@aris](https://www.ruby-forum.com/u/aris)\ **Post date:** [November 8, 2012, 6:34pm UTC](https://www.ruby-forum.com/t/howto-square-ff-require-gruel/224355/1 "2012-11-08T18:34:38Z")
Tom & Gong, It seems I have the same problem as you two have been discussing. I create a module (howto) using the gr\_modtool and added hwto\_square\_ff using ‘gr\_modtool add’. I completed the tutorial, but cannot make anything. I went back and created a build directory and then ran cmake …/ as described, but I reveice an error stating, “CMake error as CMakeLists.txt:89 (message): Gruel required to compile”. I have the FinfGruel cmake file in the cmake/Modules directory, but it still won’t work. Thanks ---
**Author:** ![Brooke\_H](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/77aa72/32.png) [@Brooke\_H](https://www.ruby-forum.com/u/Brooke_H)\ **Post date:** [November 8, 2012, 7:04pm UTC](https://www.ruby-forum.com/t/howto-square-ff-require-gruel/224355/2 "2012-11-08T19:04:26Z")
On 11/08/2012 09:33 AM, Brooke H. wrote: > FindGruel its looking for your install of gnuradio. Which is not found. I think if you are using the default install prefix this is pretty much automatic (/usr and /usr/local) You can always manually tell cmake how to find Gruel headers and libraries by using GRUEL\_LIBRARIES GRUEL\_INCLUDE\_DIRS. cmake source\_dir -DGRUEL\_LIBRARIES=path to library -DGRUEL\_INCLUDE\_DIRS=path to include Or using cmake-gui -josh ---
**Author:** ![Brooke\_H](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/77aa72/32.png) [@Brooke\_H](https://www.ruby-forum.com/u/Brooke_H)\ **Post date:** [November 8, 2012, 8:11pm UTC](https://www.ruby-forum.com/t/howto-square-ff-require-gruel/224355/3 "2012-11-08T20:11:38Z")
Perhaps this is a bug, but I can’t reproduce that error, not with 3.6.1, master, next nor with any branch of gr\_modtool. Please tell us - where libgruel.so is (if it’s somewhere exotic, Josh’s answer is all you need) - which version of GNU Radio you’re using. Also, try and build gr-howto-write-a-block to narrow down the error. M On Thu, Nov 08, 2012 at 12:33:30PM -0500, Brooke H. wrote: > directory, but it still won’t work. > > Thanks > * * * > > Discuss-gnuradio mailing list > [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > [Discuss-gnuradio Info Page](https://lists.gnu.org/mailman/listinfo/discuss-gnuradio) – Karlsruhe Institute of Technology (KIT) Communications Engineering Lab (CEL) Dipl.-Ing. Martin B. Research Associate Kaiserstraße 12 Building 05.01 76131 Karlsruhe Phone: +49 721 608-43790 Fax: +49 721 608-46071 www.cel.kit.edu KIT – University of the State of Baden-Württemberg and National Laboratory of the Helmholtz Association ---
**Author:** ![Brooke\_H](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/77aa72/32.png) [@Brooke\_H](https://www.ruby-forum.com/u/Brooke_H)\ **Post date:** [November 9, 2012, 3:02am UTC](https://www.ruby-forum.com/t/howto-square-ff-require-gruel/224355/4 "2012-11-09T03:02:58Z")
> I have tryed the gr-howto-write-a-block in gnuradio-3.6.1 source code.As > I want to use it in grc,I add this > ‘add\_subdirectory(gr-howto-write-a-block)’ in > $PREFIX/gnuradio-3.6.1/CMakeList.txt.I think this is the point that > makes CMake fail. And libgruel.so exists in > $PREFIX/gnuradio-3.6.1/build/gruel/src/lib. Basically, dont do that. Every gr-\* directory (gr-directory, gr-filter…) is an example of how to create blocks as an _in-tree_ build. However, gr-howto-write-a-block is an example of how to create blocks as an _out-of-tree_ build. You must install gnuradio, and treat gr-howto-write-a-block as a top level build system, and configure gr-howto-write-a-block with paths to the installed gnuradio files. -josh ---
**Author:** ![Brooke\_H](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/77aa72/32.png) [@Brooke\_H](https://www.ruby-forum.com/u/Brooke_H)\ **Post date:** [November 9, 2012, 2:34am UTC](https://www.ruby-forum.com/t/howto-square-ff-require-gruel/224355/5 "2012-11-09T02:34:20Z")
Martin B. (CEL) wrote: > M > > > back and created a build directory and then ran cmake ../ as described, but I > > reveice an error stating, “CMake error as CMakeLists.txt:89 (message): Gruel > > required to compile”. I have the FinfGruel cmake file in the cmake/Modules > > directory, but it still won’t work. > > > > Thank > > I have tryed the gr-howto-write-a-block in gnuradio-3.6.1 source code.As > > I want to use it in grc,I add this > > ‘add\_subdirectory(gr-howto-write-a-block)’ in > > $PREFIX/gnuradio-3.6.1/CMakeList.txt.I think this is the point that > > makes CMake fail. And libgruel.so exists in > > $PREFIX/gnuradio-3.6.1/build/gruel/src/lib.