Okay, well I'll work with that link then. Here's my noted in case they help anyone else, because that document is reasonable at pushing people to a desired state, but not very helpful for testing various conditions.
You are using an outdated version of the client (upgrade to the newest version, available here166, and try again)
Nope, latest beta + curl test below fails too.
Rewrite module is not enabled / not configured or not working properly
Apache is doing all sort of rewrites, so it's enabled and working properly. Some info is missing from that page.
1) How do I test that an owncloud-specific rewrite rule is working -- how can I test this dependency?
2) Where is the owncloud rewrite config? What rewrites are needed?
There are no requirements for a rewrite config at https://doc.owncloud.org/server/10.0/admin_manual/installation/source_installation.html, so I'll assume that the working module is all that's needed and move on, but some way to test this would be helpful.
On the server running owncloud, a separate WebDAV module is enabled, and it interferes with owncloud's built-in WebDAV module.
If I run
curl -u name -i -X PROPFIND https://server/mycloud/remote.php/webdav
I get a response that includes WWW-Authenticate: Basic realm="ownCloud" and some oc cookies, so I thinks that's fine there.
You could have some required HTTP verbs disabled
I think the PROPFIND above covers these, because if it was a limited verb I'd get a 405 error not a 401 error.
Your webserver has configured a Basic Auth authentication
It does, but only for other directories, so that's not it, surely?
Your webserver isn't passing your credentials to php in the standard way (You will see a message like "Sabre_DAV_Exception_NotAuthenticated No basic authentication headers were found").
I don't get that error message in the log, I get "You are using a fallback implementation of the intl extension.", and I don't think that's the cause of my problem. Happy to be corrected on this!
You have a security software/module (like SELinux) running
Prints a 1, so that's not it.
One or more module listen in this146 FAQ is installed / enabled
Nope, I couldn't find any of those setup except Basic Auth, ETags are MTime and Size.
You might be running ownCloud behind a reverse proxy; in that case you should ensure that your proxy is configured to pass WebDAV queries. See this forum thread for the case of the Pound reverse proxy: https://forum.owncloud.org/viewtopic.php?t=4949103
You are using php in cgi mode on CentOS79.
Hmmmmm... How do I check this? The linked post doesn't tell me, so:
Server API CGI/FastCGI
Aha. So, OC doens't work with PHP in CGI mode.
Does anyone know why this might be? Can I find more detail on this? Can developers chime in on how to debug this maybe? I have 'debug' => true, in my php config, but I'm not getting any more detail in the log.
I'd rather (get help to) figure out why and change that if possible than to just change the server config, though I accept that it's going to be a more popular view to push the server to a known good/supported config instead.