The hello demo doesn't work

[marius851000]

Hello. The hello demo doesn't work, returning an error like 'PermissionError: [Errno 13] Permission denied: 'aclocal.m4''

This is due to (if I'm ok) the folder being Read-Only in the store, and then copied to the tempory folder for compilation, which is then read only.

I also have a diferent and probably more important problem with it: When I run the hello demo multiple time, I have the error 'FileNotFoundError: [Errno 2] No such file or directory: '/tmp/pylightnix_hello_demo/2f56e6f987a1da0271915894ca19e28f-hello-src/config.json'
' I effectively doesn't have a folder named like that, but I have a context.json in one of it's subfolder.

[sergei-mironov]

Hi. thanks for the report. I recently added read-only mode for storage and forget to rebuild demos. Now I think master has a solution for the 'Permission denied' part of the problem. Fixes are:

1. Core preserves executable bit when changing permission ro read-only
2. Hello realizer now has to set 'rw' mode back before work with the sources

'FileNotFound' part is not yet clear for me. File config.json normally should always exist in derivation folders like /tmp/pylightnix_hello_demo/2f56e6f987a1da0271915894ca19e28f-hello-src/ (context.json is also a mandatory file, but I think it is unrelated here)

[sergei-mironov]

Ok, second part now looks clear too. Turns out that rmtree() call can't delete reaonly folders, but since config.json was not protected, it actually was deleted. So the storage was corrupted by rmtree in your case (in this demo we clear the storage to prevent caching and demonstrate how do realizers work). I've posted a fix with a more powerful remover function. I'll also make config.json write-protected soon.

The demo should already work now, please check