Cannot remove folder that is on Matlab path from outside of Matlab

Hi,

we are using a library that adds folders to the Matlab path. In addition we have an external build system that tries to delete temporary folders before building mex-Files and copying Simulink and Matlab files. For an unknown reason, Matlab prevents the removal of these folder as long they are on the Matlab path. I tried bdclose('all'), clear functions, clear mex, clear all, nothing helps. Why is Matlab preventing the removal?

I also tried to reproduce it manually. But than it works. It happens only with folders that have been added by this library.

Regards

Markus

[dpb]

The latter is the klew that it is in the installation process of the library, not MATLAB itself that is setting the folder attributes, so dig into their install process/script.

Oh, another thought...ML for performance reasons caches the functions; normally |clear mex| lets development tools recompile and replace mex files; in what form is the library distributable; is it a DLL perchance? That may be locked by the system OS...

[Rigel Ifland]

I'm also having this problem, and it's pretty frustrating because it means that if anyone adds my code (stored on a network drive) to their path, I can't delete it until they have closed MATLAB or removed it from their path.

I can reproduce the problem (which seems to do with packages) by creating a few files:

demoFolder
	└ +demoPackage
		└ demoFile.m  

If I add demoFolder to the path, I can't delete it from outside MATLAB. Once I remove it from the path I can.

MATLAB 2018b, Windows 10

[dpb]

OTOH, it would be pretty frustrating for the user if they were using said code and all of a sudden it disappears in the middle of something they're doing, too...

Answer 1

[Markus]

No, it is mainly matlab and Simulink files. But the problem happens for any folder, no matter if it contains Simulink, Matlab or mex files

Answer 2

[Giles]

I'm having what appears to be the same issue. In my case I've narrowed it down to something pretty simple: If there is a folder that has subfolders, and and at least one subfolder is on the MATLAB search path, then you can't delete the folder when MATLAB is running.

You can delete it if it has no subfolders on the search path, including if only it is on the search path and none of its subfolders.

Any ideas as to why?