Thanks for the report.

Can you attach the full build log with the verbose settings enabled as shown at the top of the page?

Thanks for the detail, we cannot replicate this currently, however one option is to automate the file rename process in your project.

If you add a Local board.txt to the project (vMicro > Add Code > Add Local board.txt), and paste in the below, it will rename the null.d file to null.d.txt in the build folder:

recipe.hooks.postbuild.1.pattern=cmd.exe /c ren "{build.path}\null.d" "null.d.txt" 

The location in your build folder may be different, and you may wish to delete the file instead of rename it.  This happens before the copy to your intermediate onedrive folder occurs.

Can you attach a copy of the null.d file so we can review its contents in the hope we can find where it is coming from?

Thanks for the file.

The dependency file lists some ESP32 dependencies, but your initial build log was for an Arduino Nano board.

Can you attach the latest build log which generated the attached null.d file?

Thanks for the update, we can only see the sketch-gcc-e_d.txt file on the previous post, but not the build log.

The .vmpreproc folder should not be copied over to the output directory, this should only happen when the "Build In Intermediate" is enabled, which would not be what you want in this scenario.

Can you confirm whether the .vmpreproc folder re-appears in your onedrive folder after deleting it and performing another build? (and attach the log from that build)

Glad it is working as expected now on your machine.

The entire contents of the build folder in Temp\VMBuilds\(ProjectName)\(Board)\(Configuration) can be deleted as these are recreated on each build.

Rebuilding a project will clean and build all project files for that project only.  Rebuild Solution will do this for all projects in the solution, and also clears the shared cache for the core in use.

Thanks for the update.

We have replicated the sketch-gcc-e.d file being created which we will investigate, however we are struggling to recreate the nul.d file issue currently.

Would it be possible to ZIP the entire solution folder and email it to us so we can investigate further? (delete the .vs folder first to reduce the size of the ZIP)

Thanks for the files, just to confirm have you renamed the "_nul.d" to include the underscore on the start of the filename?

Thanks for all of the detail on this and working through the issue with us.

The latest release (22.08.23.01) will resolve this, and it is available for download from the top of the board below:
https://www.visualmicro.com/forums/YaBB.pl?board=VS_ARDUINO_EXT_RELEASES