Re: gnome-tweak-tool tweaks

[iyzsong@member.fsf.org (宋文武)]

ludo@gnu.org (Ludovic Courtès) writes:

> [...]
>
>> I/O error : Permission denied
>> I/O error : Permission denied
>> Failed to write XML file; For permission problems, try rerunning as root
>
> I found that string comes from ‘shared-mime-info’, which is itself used
> by the ‘xdg-mime-database’ hook in (guix profiles) (a hook that runs
> when the profile is created to update the MIME database):
>
> static gboolean save_xml_file(xmlDocPtr doc, const gchar *filename, GError **error)
> {
> #if LIBXML_VERSION > 20400
> 	if (xmlSaveFormatFileEnc(filename, doc, "utf-8", 1) < 0)
> 	{
> 		g_set_error(error, G_FILE_ERROR, G_FILE_ERROR_FAILED,
> 			    "Failed to write XML file; For permission problems, try rerunning as root");
> 		return FALSE;
> 	}
> #else
>
> 宋文武: any idea what the problem might be?  Perhaps
> ‘update-mime-database’ is trying to write to /gnu/store/…-something?
Yep, it happends when '$out/share/mime/application' is not writable.
The xml files under 'application' are going to be generated by
update-mime-database, and the shared-mime-info package has it
pre-generated, so after union "share/mime", an un-writable 'application'
directory point to the store will cause the problem.

Commit 359f06aa fix this by union the "share/mime/packages" directory.

>
> Also, it’s a problem that ‘update-mime-database’ returns 0 here, as
> seems to be the case.
It returns 256 here for the problem, but the derivation still built and
profile got updated, I have no idea about this :-

Does a failing hook (returns #f) supposed to top the profile update?