Problem with local (private) IPM registry

I'm trying out the package manager (IPM). I'm trying to create a local (private) registry. To me it looks like the local registry installation succeeded but I can't figure out how to use it.

I'm using latest stable v0.7.3.

I have uploaded one module there (as told in one forum post):

$ curl http://localhost:52774/registry/
{"version":"1.3.2"}
$ curl http://localhost:52774/registry/packages/-/all
[{"name":"objectscript-math","description":"Math library for InterSystems ObjectScript","repository":"https://github.com/psteiwer/ObjectScript-Math/","origin":"","versions":["0.0.5"],"is_owner":0}]

Now trying to use that repository:

zpm:IPMTEST1>list-installed -tree
zpm-registry 1.3.2
└──yaml-utils 0.1.4

zpm:IPMTEST1>repo -list

registry
        Source:                 https://pm.community.intersystems.com
        Enabled?                Yes
        Available?              Yes
        Use for Snapshots?      Yes
        Use for Prereleases?    Yes
        Is Read-Only?           No
        Deployment Enabled?     No

zpm:IPMTEST1>repo -name registry -list-modules
[a long list of modules removed for readability]

zpm:IPMTEST1>repo -name local -remote -url http://localhost:52774/registry/

local
        Source:                 http://localhost:52774/registry/
        Enabled?                Yes
        Available?              No
        Use for Snapshots?      Yes
        Use for Prereleases?    Yes
        Is Read-Only?           No
        Deployment Enabled?     No
zpm:IPMTEST1>repo -list

local
        Source:                 http://localhost:52774/registry/
        Enabled?                Yes
        Available?              No
        Use for Snapshots?      Yes
        Use for Prereleases?    Yes
        Is Read-Only?           No
        Deployment Enabled?     No

registry
        Source:                 https://pm.community.intersystems.com
        Enabled?                Yes
        Available?              Yes
        Use for Snapshots?      Yes
        Use for Prereleases?    Yes
        Is Read-Only?           No
        Deployment Enabled?     No

zpm:IPMTEST1>repo -name local -list-modules

zpm:IPMTEST1>

Why my local repository is not available (Available? No) and why I don't see the objectscript-math module here?

There is also always a significant delay in operations with local repository, like some kind of timeout.