building.md doesn't specify that pyupm_utilities needs to be made as well if doing single module installs

[vulq]

This took me hours to figure out, if not doing the full install but just selecting a single module (i.e. make _pyupm_bmi160-python3), you will get an error on import saying that the module doesn't exist (ImportError: No module named '_pyupm_bmi160'). To resolve this, you need to also install the utilities module (make _pyupm_utilities-python3).

Please include this in the build docs to help others who may have this issue.

[pylbert]

@vulq, did you 'make install' after building your modules? If so, can you provide more info and we can get this sorted out.

You can build/load a single module from your build-tree since binaries in the build tree have link dependencies specified with RPATH. These are stripped upon install and rely on the run time linker/loader.

If you use 'make install,' the necessary dependencies will be installed. Generally you should update the linker cache using 'ldconfig' before attempting to import a UPM python module - this could be added to the build docs.

If you are not using the UPM 'make install' mechanism to install the necessary content, you may need to do a small amount of hacking to get things working (e.g. ensure dependencies are in the correct places). Note: using the build-tree binaries means you will have an RPATH pointing back to the build-tree (which can trip you up later on).

[vulq]

I did do ldconfig and it didn't seem to have an effect. I didn't do a full make install since it was linking libraries that were not made; I was under the assumption, as per the docs, that I would only have to make install under build/src/bmi160 after doing make _pyupm_bmi160-python3. The reason the module could not be imported was because of a dependency on libupm-utilities.so. I feel like if this is a dependency for the bmi160 module, it should be included when building just a specific module - the docs seem to imply that all dependencies will be built.

[pylbert]

@vulq, I see.

The 'all' target under build/src/bmi160 comprehends building bmi160 (and _pyupm_bmi160-python3) and all necessary dependencies, but can only install components from this level.

I've added a note with #643. Let me know if this is enough clarification.

[vulq]

Great, thanks! So the only way to install those dependencies would be to do a make install in upm/build?

[pylbert]

Correct.

I generally do all my building/installing from this level. You can limit the number of directories CMake adds with the MODULE_LIST variable which helps to speed up generation and build time.

Example:

cmake -DMODULE_LIST=bmi160 .. make -j4 make install

[vulq]

Great, thank you so much!

[Propanu]

You can actually go and install the dependencies manually from each src dir for the internal ones, and it would still be faster than running make install at top level in the build dir. The install target dependencies are missing from cmake and that's why a full installs work well. Having these would actually help package and distribute modules for python and node.js easier too.

[pylbert]

@vulq, the doc updates are merged in 8f63914d76f8d6ff9971e3a97141012a2d78daf3. OK to close?