Disable SecretService and KWallet backends if the corresponding names are not available on D-Bus

[mitya57]

First, check if the name is already taken by some application. If no, check if the service can be activated dynamically.

@takluyver Please review this if you have time. And thanks again for your suggestion!

This fixes #162, #434, #473.

[takluyver]

No problem, thank you for doing the work with it. :-)

For some reason I can't see the logs from the Azure pipelines builds that are failing - I don't know if that's a random glitch, or if they're set to private.

[jaraco]

Right - please disregard the Azure and Appveyor integrations. I'm migrating projects to github actions. I see I haven't done that here yet. I'll do that in master and then a rebase ought to clear things up.

[jaraco]

I've rebased to master to fix CI.

[mitya57]

Thanks you @takluyver and @jaraco for your comments! I will address them tomorrow.

[jaraco]

Regardless the solution you come up with, the general approach seems suitable.

[takluyver]

The code changes LGTM now, though I've not tried them locally.

Just to reiterate what I said on #473: this won't altogether eliminate this kind of hang, but I think that delays when calling keyring functions are more palatable than delays on import. I'm working on changes to Jeepney which will include the ability to set a timeout on blocking method calls, which we could use to limit how long it waits.

[mitya57]

this won't altogether eliminate this kind of hang, but I think that delays when calling keyring functions are more palatable than delays on import.

I think there are many cases where keyring is imported but isn't going to be used. So for such users the problem will be solved.

I'm working on changes to Jeepney which will include the ability to set a timeout on blocking method calls, which we could use to limit how long it waits.

I saw that. Thanks!

I have made SecretStorage 3.2.0 release now, so this is ready for merge.

[jaraco]

Expect this build to release v21.5.0.