# Building an OOT modules with an In Tree Dependency **URL:** \ **Category:** GNU Radio\ **Created:** [July 30, 2015, 11:27pm UTC](https://www.ruby-forum.com/t/building-an-oot-modules-with-an-in-tree-dependency/242817 "2015-07-30T23:27:42Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Rafa\_F](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/958977/32.png) [@Rafa\_F](https://www.ruby-forum.com/u/Rafa_F)\ **Post date:** [July 30, 2015, 11:27pm UTC](https://www.ruby-forum.com/t/building-an-oot-modules-with-an-in-tree-dependency/242817/1 "2015-07-30T23:27:42Z")
I’m trying to make an out of tree module based on blocks::file\_sink that has some additional functionality I need. Right now, I’ve built it OOT, but an having trouble getting it to work. The code (file\_sink\_impl.cc, file\_sink\_impl.h, and file\_sink.h --\> actual names are different so there are no conflicts) are all identical to the ones in tree. I used gr-modtool to create the OOT modules with this block and it makes and installs fine. However, when I try to use it, I get the following error: AttributeError: ‘file\_sink\_sptr’ object has no attribute ‘set\_unbuffered’ What I think is happening here is that the OOT version of my code isn’t linking to the file\_sink\_base in gnuradio-blocks to inherit this function. Browsing previous mail lists, Marcus M. noted in the thread ’ [Discuss-gnuradio] Out of Tree linker error… libgnuradio-MYMOD.so:’ that the problem might be in my cmake files. He referenced gr-specest as an example which uses in tree modules. I compared the cmakelists.txt in gr-specest to the OOT module directory and in the OOT/lib directory and added the BLOCKS references in the appropriate places. However, this still hasn’t solved the problems. Are there any other steps necessary to make and install an OOT modules with in tree dependencies? All of this is running on Ubuntu 14.04LTS with gnuradio 3.7.7.1 ---
**Author:** ![ValentaS\_Chris\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/74df32/32.png) [@ValentaS\_Chris\_R](https://www.ruby-forum.com/u/ValentaS_Chris_R)\ **Post date:** [July 31, 2015, 4:27pm UTC](https://www.ruby-forum.com/t/building-an-oot-modules-with-an-in-tree-dependency/242817/2 "2015-07-31T16:27:45Z")
On Thu, Jul 30, 2015 at 5:26 PM, Valenta, Chris R. \< [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote: > AttributeError: ‘file\_sink\_sptr’ object has no attribute ‘set\_unbuffered’ > hasn’t solved the problems. Are there any other steps necessary to make > and install an OOT modules with in tree dependencies? All of this is > running on Ubuntu 14.04LTS with gnuradio 3.7.7.1 The first thing that comes to mind when we see this is that you haven’t added all of the public functions of your block to the public header file (file\_sink.h), but you say that’s identical. Still probably worth checking on that file to make sure. Have you looked at your swig directory’s .i file? That needs to properly reference your block to export it into Python. It seems like this is ok since you’re getting as far as to see the error on the method, not the block. Again, though, something to check. So this is just you replicating the file sink blocks completely? You aren’t trying to inherit from them or use them internally, are you? That might cause other issues. Tom ---
**Author:** ![ValentaS\_Chris\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/74df32/32.png) [@ValentaS\_Chris\_R](https://www.ruby-forum.com/u/ValentaS_Chris_R)\ **Post date:** [July 31, 2015, 4:52pm UTC](https://www.ruby-forum.com/t/building-an-oot-modules-with-an-in-tree-dependency/242817/3 "2015-07-31T16:52:17Z")
So the function (set\_unbuffered) that’s coming up as not being found is in file\_sink\_base.h which is included in the file\_sink.h so I’m pretty sure I’m ok here. The swig file just includes file\_sink.h….I tried adding file\_sink\_base.h to this as well, but it didn’t change anything. For the time being, I’m replicating the file\_sink block exactly (except the name) to try and get it to compile OOT. However, since file\_sink depends on file\_sink\_base, which I’m not copying, I think there are problems linking to it. Would it be better to also copy file\_sink\_base to my OOT module? From: removed\_email\_address@domain.invalid [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Tom R. Sent: Friday, July 31, 2015 10:27 AM To: Valenta, Chris R. Cc: removed\_email\_address@domain.invalid Subject: Re: [Discuss-gnuradio] Building an OOT modules with an In Tree Dependency On Thu, Jul 30, 2015 at 5:26 PM, Valenta, Chris R. \ wrote: I’m trying to make an out of tree module based on blocks::file\_sink that has some additional functionality I need. Right now, I’ve built it OOT, but an having trouble getting it to work. The code (file\_sink\_impl.cc, file\_sink\_impl.h, and file\_sink.h → actual names are different so there are no conflicts) are all identical to the ones in tree. I used gr-modtool to create the OOT modules with this block and it makes and installs fine. However, when I try to use it, I get the following error: AttributeError: ‘file\_sink\_sptr’ object has no attribute ‘set\_unbuffered’ What I think is happening here is that the OOT version of my code isn’t linking to the file\_sink\_base in gnuradio-blocks to inherit this function. Browsing previous mail lists, Marcus M. noted in the thread ‘ [Discuss-gnuradio] Out of Tree linker error… libgnuradio-MYMOD.so:‘ that the problem might be in my cmake files. He referenced gr-specest as an example which uses in tree modules. I compared the cmakelists.txt in gr-specest to the OOT module directory and in the OOT/lib directory and added the BLOCKS references in the appropriate places. However, this still hasn’t solved the problems. Are there any other steps necessary to make and install an OOT modules with in tree dependencies? All of this is running on Ubuntu 14.04LTS with gnuradio 3.7.7.1 The first thing that comes to mind when we see this is that you haven’t added all of the public functions of your block to the public header file (file\_sink.h), but you say that’s identical. Still probably worth checking on that file to make sure. Have you looked at your swig directory’s .i file? That needs to properly reference your block to export it into Python. It seems like this is ok since you’re getting as far as to see the error on the method, not the block. Again, though, something to check. So this is just you replicating the file sink blocks completely? You aren’t trying to inherit from them or use them internally, are you? That might cause other issues. Tom ---
**Author:** ![ValentaS\_Chris\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/74df32/32.png) [@ValentaS\_Chris\_R](https://www.ruby-forum.com/u/ValentaS_Chris_R)\ **Post date:** [July 31, 2015, 5:02pm UTC](https://www.ruby-forum.com/t/building-an-oot-modules-with-an-in-tree-dependency/242817/4 "2015-07-31T17:02:49Z")
On Fri, Jul 31, 2015 at 10:50 AM, Valenta, Chris R. \< [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote: > For the time being, I’m replicating the file\_sink block exactly (except > the name) to try and get it to compile OOT. However, since file\_sink > depends on file\_sink\_base, which I’m not copying, I think there are > problems linking to it. > > Would it be better to also copy file\_sink\_base to my OOT module? You should be able to use file\_sink\_base from libgnuradio-blocks.so, so no, keep that one in tree so you’re not carrying around extra stuff. First, do you have BLOCKS as one of the GNU Radio required components in your CMakeLists.txt file? Also, and I suspect this might be the real problem, do you “#define BLOCKS\_API” in you .i file? There should be a #define for your module’s name already; just add this line here along with that one. Tom ---
**Author:** ![ValentaS\_Chris\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/74df32/32.png) [@ValentaS\_Chris\_R](https://www.ruby-forum.com/u/ValentaS_Chris_R)\ **Post date:** [July 31, 2015, 7:54pm UTC](https://www.ruby-forum.com/t/building-an-oot-modules-with-an-in-tree-dependency/242817/5 "2015-07-31T19:54:01Z")
Ah, so I figured it out. Not only did I need to add #define BLOCKS\_API to my swig .i file, but I also had to add %include “gnuradio/blocks/file\_sink\_base.h” as well. From: Valenta, Chris R. Sent: Friday, July 31, 2015 11:30 AM To: ‘Tom R.’ Cc: removed\_email\_address@domain.invalid Subject: RE: [Discuss-gnuradio] Building an OOT modules with an In Tree Dependency Yes, blocks is included in the cmakelists.txt as set(GR\_REQUIRED\_COMPONENTS RUNTIME BLOCKS) as well as a link directory GNURADIO\_BLOCKS\_LIBRARY\_DIRS. Its also in the /lib cmakelists.txt as a target\_link\_library GNURADIO\_BLOCKS\_LIBRARIES. BLOCKS\_API was not in the swig .i file. I added this, ran make clean, make, and installed and still get the same error. From: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Tom R. Sent: Friday, July 31, 2015 11:02 AM To: Valenta, Chris R. Cc: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Building an OOT modules with an In Tree Dependency On Fri, Jul 31, 2015 at 10:50 AM, Valenta, Chris R. \ wrote: So the function (set\_unbuffered) that’s coming up as not being found is in file\_sink\_base.h which is included in the file\_sink.h so I’m pretty sure I’m ok here. The swig file just includes file\_sink.h….I tried adding file\_sink\_base.h to this as well, but it didn’t change anything. For the time being, I’m replicating the file\_sink block exactly (except the name) to try and get it to compile OOT. However, since file\_sink depends on file\_sink\_base, which I’m not copying, I think there are problems linking to it. Would it be better to also copy file\_sink\_base to my OOT module? You should be able to use file\_sink\_base from libgnuradio-blocks.so, so no, keep that one in tree so you’re not carrying around extra stuff. First, do you have BLOCKS as one of the GNU Radio required components in your CMakeLists.txt file? Also, and I suspect this might be the real problem, do you “#define BLOCKS\_API” in you .i file? There should be a #define for your module’s name already; just add this line here along with that one. Tom From: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Tom R. Sent: Friday, July 31, 2015 10:27 AM To: Valenta, Chris R. Cc: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Building an OOT modules with an In Tree Dependency On Thu, Jul 30, 2015 at 5:26 PM, Valenta, Chris R. \ wrote: I’m trying to make an out of tree module based on blocks::file\_sink that has some additional functionality I need. Right now, I’ve built it OOT, but an having trouble getting it to work. The code (file\_sink\_impl.cc, file\_sink\_impl.h, and file\_sink.h → actual names are different so there are no conflicts) are all identical to the ones in tree. I used gr-modtool to create the OOT modules with this block and it makes and installs fine. However, when I try to use it, I get the following error: AttributeError: ‘file\_sink\_sptr’ object has no attribute ‘set\_unbuffered’ What I think is happening here is that the OOT version of my code isn’t linking to the file\_sink\_base in gnuradio-blocks to inherit this function. Browsing previous mail lists, Marcus M. noted in the thread ‘ [Discuss-gnuradio] Out of Tree linker error… libgnuradio-MYMOD.so:‘ that the problem might be in my cmake files. He referenced gr-specest as an example which uses in tree modules. I compared the cmakelists.txt in gr-specest to the OOT module directory and in the OOT/lib directory and added the BLOCKS references in the appropriate places. However, this still hasn’t solved the problems. Are there any other steps necessary to make and install an OOT modules with in tree dependencies? All of this is running on Ubuntu 14.04LTS with gnuradio 3.7.7.1 The first thing that comes to mind when we see this is that you haven’t added all of the public functions of your block to the public header file (file\_sink.h), but you say that’s identical. Still probably worth checking on that file to make sure. Have you looked at your swig directory’s .i file? That needs to properly reference your block to export it into Python. It seems like this is ok since you’re getting as far as to see the error on the method, not the block. Again, though, something to check. So this is just you replicating the file sink blocks completely? You aren’t trying to inherit from them or use them internally, are you? That might cause other issues. Tom ---
**Author:** ![ValentaS\_Chris\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/74df32/32.png) [@ValentaS\_Chris\_R](https://www.ruby-forum.com/u/ValentaS_Chris_R)\ **Post date:** [July 31, 2015, 7:58pm UTC](https://www.ruby-forum.com/t/building-an-oot-modules-with-an-in-tree-dependency/242817/6 "2015-07-31T19:58:07Z")
On Fri, Jul 31, 2015 at 1:52 PM, Valenta, Chris R. \< [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote: > Ah, so I figured it out. Not only did I need to add #define BLOCKS\_API to > my swig .i file, but I also had to add %include > “gnuradio/blocks/file\_sink\_base.h” as well. Ah, of course! Good catch. We should have this documented somewhere – how to use GNU Radio classes and blocks in OOT projects. Tom ---
**Author:** ![ValentaS\_Chris\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/74df32/32.png) [@ValentaS\_Chris\_R](https://www.ruby-forum.com/u/ValentaS_Chris_R)\ **Post date:** [July 31, 2015, 5:30pm UTC](https://www.ruby-forum.com/t/building-an-oot-modules-with-an-in-tree-dependency/242817/7 "2015-07-31T17:30:51Z")
Yes, blocks is included in the cmakelists.txt as set(GR\_REQUIRED\_COMPONENTS RUNTIME BLOCKS) as well as a link directory GNURADIO\_BLOCKS\_LIBRARY\_DIRS. Its also in the /lib cmakelists.txt as a target\_link\_library GNURADIO\_BLOCKS\_LIBRARIES. BLOCKS\_API was not in the swig .i file. I added this, ran make clean, make, and installed and still get the same error. From: removed\_email\_address@domain.invalid [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Tom R. Sent: Friday, July 31, 2015 11:02 AM To: Valenta, Chris R. Cc: removed\_email\_address@domain.invalid Subject: Re: [Discuss-gnuradio] Building an OOT modules with an In Tree Dependency On Fri, Jul 31, 2015 at 10:50 AM, Valenta, Chris R. \ wrote: So the function (set\_unbuffered) that’s coming up as not being found is in file\_sink\_base.h which is included in the file\_sink.h so I’m pretty sure I’m ok here. The swig file just includes file\_sink.h….I tried adding file\_sink\_base.h to this as well, but it didn’t change anything. For the time being, I’m replicating the file\_sink block exactly (except the name) to try and get it to compile OOT. However, since file\_sink depends on file\_sink\_base, which I’m not copying, I think there are problems linking to it. Would it be better to also copy file\_sink\_base to my OOT module? You should be able to use file\_sink\_base from libgnuradio-blocks.so, so no, keep that one in tree so you’re not carrying around extra stuff. First, do you have BLOCKS as one of the GNU Radio required components in your CMakeLists.txt file? Also, and I suspect this might be the real problem, do you “#define BLOCKS\_API” in you .i file? There should be a #define for your module’s name already; just add this line here along with that one. Tom From: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Tom R. Sent: Friday, July 31, 2015 10:27 AM To: Valenta, Chris R. Cc: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Building an OOT modules with an In Tree Dependency On Thu, Jul 30, 2015 at 5:26 PM, Valenta, Chris R. \ wrote: I’m trying to make an out of tree module based on blocks::file\_sink that has some additional functionality I need. Right now, I’ve built it OOT, but an having trouble getting it to work. The code (file\_sink\_impl.cc, file\_sink\_impl.h, and file\_sink.h → actual names are different so there are no conflicts) are all identical to the ones in tree. I used gr-modtool to create the OOT modules with this block and it makes and installs fine. However, when I try to use it, I get the following error: AttributeError: ‘file\_sink\_sptr’ object has no attribute ‘set\_unbuffered’ What I think is happening here is that the OOT version of my code isn’t linking to the file\_sink\_base in gnuradio-blocks to inherit this function. Browsing previous mail lists, Marcus M. noted in the thread ‘ [Discuss-gnuradio] Out of Tree linker error… libgnuradio-MYMOD.so:‘ that the problem might be in my cmake files. He referenced gr-specest as an example which uses in tree modules. I compared the cmakelists.txt in gr-specest to the OOT module directory and in the OOT/lib directory and added the BLOCKS references in the appropriate places. However, this still hasn’t solved the problems. Are there any other steps necessary to make and install an OOT modules with in tree dependencies? All of this is running on Ubuntu 14.04LTS with gnuradio 3.7.7.1 The first thing that comes to mind when we see this is that you haven’t added all of the public functions of your block to the public header file (file\_sink.h), but you say that’s identical. Still probably worth checking on that file to make sure. Have you looked at your swig directory’s .i file? That needs to properly reference your block to export it into Python. It seems like this is ok since you’re getting as far as to see the error on the method, not the block. Again, though, something to check. So this is just you replicating the file sink blocks completely? You aren’t trying to inherit from them or use them internally, are you? That might cause other issues. Tom ---
**Author:** ![ValentaS\_Chris\_R](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/v/74df32/32.png) [@ValentaS\_Chris\_R](https://www.ruby-forum.com/u/ValentaS_Chris_R)\ **Post date:** [August 1, 2015, 1:56am UTC](https://www.ruby-forum.com/t/building-an-oot-modules-with-an-in-tree-dependency/242817/8 "2015-08-01T01:56:17Z")
If we don’t just document with comments in the proper places in the OOT structure, I was thinking we could have the user list GR required components in the gr\_modtool interactive configuration. It wouldn’t solve all problems like the file\_sink\_base issue, but it would be a good start. Sean From: discuss-gnuradio-bounces+sean.nowlan=removed\_email\_address@domain.invalid [[mailto:discuss-gnuradio-bounces+sean.nowlan=removed\_email\_address@domain.invalid](mailto:discuss-gnuradio-bounces+sean.nowlan=removed_email_address@domain.invalid)] On Behalf Of Tom R. Sent: Friday, July 31, 2015 1:57 PM To: Valenta, Chris R. Cc: removed\_email\_address@domain.invalid Subject: Re: [Discuss-gnuradio] Building an OOT modules with an In Tree Dependency On Fri, Jul 31, 2015 at 1:52 PM, Valenta, Chris R. \ wrote: Ah, so I figured it out. Not only did I need to add #define BLOCKS\_API to my swig .i file, but I also had to add %include “gnuradio/blocks/file\_sink\_base.h” as well. Ah, of course! Good catch. We should have this documented somewhere – how to use GNU Radio classes and blocks in OOT projects. Tom From: Valenta, Chris R. Sent: Friday, July 31, 2015 11:30 AM To: ‘Tom R.’ Cc: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: RE: [Discuss-gnuradio] Building an OOT modules with an In Tree Dependency Yes, blocks is included in the cmakelists.txt as set(GR\_REQUIRED\_COMPONENTS RUNTIME BLOCKS) as well as a link directory GNURADIO\_BLOCKS\_LIBRARY\_DIRS. Its also in the /lib cmakelists.txt as a target\_link\_library GNURADIO\_BLOCKS\_LIBRARIES. BLOCKS\_API was not in the swig .i file. I added this, ran make clean, make, and installed and still get the same error. From: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Tom R. Sent: Friday, July 31, 2015 11:02 AM To: Valenta, Chris R. Cc: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Building an OOT modules with an In Tree Dependency On Fri, Jul 31, 2015 at 10:50 AM, Valenta, Chris R. \ wrote: So the function (set\_unbuffered) that’s coming up as not being found is in file\_sink\_base.h which is included in the file\_sink.h so I’m pretty sure I’m ok here. The swig file just includes file\_sink.h….I tried adding file\_sink\_base.h to this as well, but it didn’t change anything. For the time being, I’m replicating the file\_sink block exactly (except the name) to try and get it to compile OOT. However, since file\_sink depends on file\_sink\_base, which I’m not copying, I think there are problems linking to it. Would it be better to also copy file\_sink\_base to my OOT module? You should be able to use file\_sink\_base from libgnuradio-blocks.so, so no, keep that one in tree so you’re not carrying around extra stuff. First, do you have BLOCKS as one of the GNU Radio required components in your CMakeLists.txt file? Also, and I suspect this might be the real problem, do you “#define BLOCKS\_API” in you .i file? There should be a #define for your module’s name already; just add this line here along with that one. Tom From: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) [[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Tom R. Sent: Friday, July 31, 2015 10:27 AM To: Valenta, Chris R. Cc: removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: [Discuss-gnuradio] Building an OOT modules with an In Tree Dependency On Thu, Jul 30, 2015 at 5:26 PM, Valenta, Chris R. \ wrote: I’m trying to make an out of tree module based on blocks::file\_sink that has some additional functionality I need. Right now, I’ve built it OOT, but an having trouble getting it to work. The code (file\_sink\_impl.cc, file\_sink\_impl.h, and file\_sink.h → actual names are different so there are no conflicts) are all identical to the ones in tree. I used gr-modtool to create the OOT modules with this block and it makes and installs fine. However, when I try to use it, I get the following error: AttributeError: ‘file\_sink\_sptr’ object has no attribute ‘set\_unbuffered’ What I think is happening here is that the OOT version of my code isn’t linking to the file\_sink\_base in gnuradio-blocks to inherit this function. Browsing previous mail lists, Marcus M. noted in the thread ‘ [Discuss-gnuradio] Out of Tree linker error… libgnuradio-MYMOD.so:‘ that the problem might be in my cmake files. He referenced gr-specest as an example which uses in tree modules. I compared the cmakelists.txt in gr-specest to the OOT module directory and in the OOT/lib directory and added the BLOCKS references in the appropriate places. However, this still hasn’t solved the problems. Are there any other steps necessary to make and install an OOT modules with in tree dependencies? All of this is running on Ubuntu 14.04LTS with gnuradio 3.7.7.1 The first thing that comes to mind when we see this is that you haven’t added all of the public functions of your block to the public header file (file\_sink.h), but you say that’s identical. Still probably worth checking on that file to make sure. Have you looked at your swig directory’s .i file? That needs to properly reference your block to export it into Python. It seems like this is ok since you’re getting as far as to see the error on the method, not the block. Again, though, something to check. So this is just you replicating the file sink blocks completely? You aren’t trying to inherit from them or use them internally, are you? That might cause other issues. Tom